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HomeMy WebLinkAboutSUP 98-03D; BRESSI RANCH PA 3 LOTS 10-13; GEOTECHNICAL INVESTIGATION; 2008-01-23GEOTECH NICAL INVESTIGATION PROPOSED BUSINESS PARK Bressi Ranch Lots 10-13 Planning Area 3 Carlsbad, California for Levine Investments 101 3'r O9J January 23, 2008 Levine Investments 1702 East Highlands Avenue, Number 310 Phoenix, Arizona 85016 SOUTHERN CALIFORNIA GEOTECHNICAL A California Corporation Attention: Mr. Andrew Cohn Project No.: 07G227-1 Subject: Geotechnical Investigation Proposed Commercial/Industrial Development Bressi Ranch Lots 10-13 Planning Area 3 NEC of Gateway Road and El Camino Real Carlsbad, California Gentlemen: lb accordance with your request, we have conducted a geotechnical investigation at the subject site. We are pleased to present this report summarizing the conclusions and recommendations developed from our investigation. We sincerely appreciate the opportunity to be of service on this project. We look forward to providing additional consulting services during the course of the project. If we may be of further assistance in any manner, please contact our office. Respectfully Submitted, SOUTHERN CALIFORNIA EOTECHNICAL, INC. Rbert G. Trazo, M.Sc., GE 55 S ni ngineer Jo . inara, CEG 2125 Pria e ogist Disribu io : 5) Addressee I No. 2655 . 12131/06 OF ~ rOMAL r-c3i` N No.2125 I ciTwuo I tJ' ENGINEERING - ow:r) OF CA i 22885 East Savi Ranch Parkway 'v Suite E 'v Yorba Linda, CA 92887-4624 - voice: (714) 685-1115 v fax: (714) 685-1118 v www.socalgeo.com TABLE OF CONTENTS 1.0 EXECUTIVE SUMMARY 1 2.0 SCOPE OF SERVICES 3 3.0 SITE AND PROJECT DESCRIPTION 4 3.1 Site Description 4 3.2 Proposed Development 4 3.3 Previous Studies 4 4.0 SUBSURFACE EXPLORATION 9 4.1 Scope of Exploration/Sampling Methods 9 4.2 Geotechnical Conditions 9 4.3 Geologic Conditions 10 5.0 LABORATORY TESTING 11 6.0 CONCLUSIONS AND RECOMMENDATIONS 13 6.1 Seismic Design Considerations 13 6.2 Geotechnical Design Considerations 15 6.3 Site Grading Recommendations 17 6.4 Construction Considerations 19 6.5 Foundation Design and Construction 21 6.6 Floor Slab Design and Construction 22 6.7 Retaining Wall Design Recommendations 23 6.8 Pavement Design Parameters 25 7.0 GENERAL COMMENTS 28 APPENDICES A Plate 1: Site Location Map Plate 2: Boring Location Plan B Boring Logs C Laboratory Test Results D Grading Guide Specifications E Seismic Design Parameters SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA CALIFORNIA Project No. 07G227-1 GEOTECHNICAL 1.0 EXECUTIVE SUMMARY Presented below is a brief summary of the conclusions and recommendations of this investigation. Since this summary is not all inclusive, it should be read in complete context with the entire report. Site Preparation Initial site preparation should include stripping of any surficial vegetation and/or significant topsoil. Based on conditions encountered at the time of the subsurface exploration, stripping of moderate grass and weed growth is expected to be necessary. The site is underlain by recently placed compacted fill soils and sandstone, siltstone and claystone bedrock. The fill soils extend to depths of up to 8± feet within the footprints of the proposed buildings and were placed under the purview of a geotechnical engineer. The existing fill soils and bedrock possess moderate to high strengths and medium expansive potentials. The compaction report prepared by Leighton and Associates indicates that the existing fill soils were placed as compacted structural fill. Leighton indicates that the existing fill soils are suitable for support of the proposed development provided that the cut/fill transitions are mitigated during precise grading. In order to provide for a new layer of structural fill that will help mitigate the variable support conditions due to the potential cut/fill transitions, It is recommended that remedial grading be performed within the proposed building pad areas. Both building pad areas are underlain by shallow bedrock and should be overexcavated to a depth of at least 3 feet below existing grade and to a depth of at least 3 feet below proposed pad grade. The depth of overexcavation should be sufficient to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations. In the remaining portions of the site, overexcavation should extend to a depth adequate to remove all surficial, weathered soils. Following completion of the recommended overexcavation, exposed soils should be evaluated by the geotechnical engineer. After the subgrade soils have been approved by the geotechnical engineer, the resulting soils may be replaced as compacted structural fill. A precise grading plan review is recommended subsequent to preparation of the plan in order to confirm the recommendations contained herein. Building Foundations Shallow foundations, supported in newly placed compacted fill. 2,500 psf maximum allowable soil bearing pressure. Minimum longitudinal steel reinforcement within strip footings: Four (4) No. 5 rebars (2 top and 2 bottom), due to the medium expansive potential of the near surface soils. Building Floor Slabs Slab-on-Grade, at least 5 inches thick. Minimum slab reinforcement: No. 3 bars at 18-inches on-center, in both directions. CALIFORNIA Project No. 07G227-1 SOUTHERN Bressl Ranch, Lots 10-13 - Carlsbad, CA Page 1 GEOTECHNICAL Pavements ASPHALT PAVEMENTS Thickness (inches) Materials Auto Parking Auto Drive Light Truck Moderate (TI = 4.5) Lanes Traffic Truck Traffic (TI = 5.5) (TI = 6.0) (TI = 7.0) Asphalt Concrete 4 4 4 4 Aggregate Base 5 8 10 13 Compacted Subgrade 12 12 12 I 12 (90% minimum compaction) I PORTLAND CEMENT CONCRETE PAVEMENTS Thickness (inches) Materials Automobile Parking Drive Lanes (TI = 5.5) and Light Truck Moderate Truck (TI = 4.5) Traffic Traffic (TI_=_6.0) (TI = 7.0) PCC 5 5½ 7 Compacted Subgrade 12 12 12 (95% minimum compaction) \. SOUTHERN Bressi Ranch, Lo 10-13 - Carlsbad, CA CALIFORNIA Project No. 07G227-1 Page 2 2.0 SCOPE OF SERVICES The scope of services performed for this project was in accordance with our Proposal No. 07P379, dated November 30, 2007. The scope of services included review of previous reports, a visual site reconnaissance, subsurface exploration, field and laboratory testing, and geotechnical engineering analysis to provide criteria for preparing design of the building foundations, building floor slabs, and parking lot pavements along with site preparation recommendations and construction considerations for the proposed development.. The evaluation of environmental aspects of this site was beyond the scope of services for this geotechriical investigation. CALIFORNIA Project No. 07G227-1 SOUTHERN Bress Ranch, Lots 10-13 - Carlsbad, CA Page 3 CEO CHNICA 3.0 SITE AND PROJECT DESCRIPTION 3.1 Site Description The subject site is located within the recently mass graded Bressi Ranch Industrial Park which is located southeast of the intersection of Palomar Airport Road and El Camino Real in the city of Carlsbad, California. The specific site is a portion of Planning Area 3, Lots 10 though 13, and is located northeast of the intersection of Gateway Road and El Camino Real. The general location of the site is illustrated on the Site Location Map, included as Plate 1 in Appendix A of this report. The subject site is an irregularly-shaped parcel, approximately 8± acres in size. Graded slopes ranging in height from 5 to 7± feet border the site to the north and east. Five (5) desilting basins were located throughout the site. The desilting basins were approximately 6 to 8± feet deep. At the time of the subsurface exploration, ground surface cover consisted of exposed soil with moderate grass and weed growth. Preliminary topographic information was obtained from a plan prepared by Smith Consulting Architects (SCA). The site plan indicates that site grades within Lots 10 through 13 range from El. 325± feet msl at the northeastern property corner to El. 295± feet msl at the southwestern property corner. 32 Proposed Development Preliminary information regarding the proposed development was obtained from the site plan prepared by Smith Consulting Architects. These plans have been provided to our office by the client. This plan indicates that the new development will consist of two (2) separate two- or three-story buildings. The proposed building footprints will be 21,700± ft2 and 25,600± ft2. Detailed structural information is not currently available. It Is, however, assumed that the buildings will be of concrete tilt-up construction, typically supported on conventional shallow foundation systems and concrete slabs on grade. Based on the assumed construction, maximum column and wall loads are expected to be on the order of 60 to 80 kips and 3 to 5 kips per linear foot, respectively. 3.3 Previous Studies As part of our investigation of the overall site, including Planning Areas PA-1 through PA-5, we were provided with several geotechnical reports. The geotechnical reports provided to us consist of preliminary and supplemental geotechnical investigations, a summary report of mass grading, and as graded reports of mass grading. The subject site has been recently rough graded to Its Project No. 07G227-1 CALIFORNIA SOUTHERN Bress Ranch, Lots 10-13 - Carlsbad, CA Page 4 current configuration under the purview of Leighton and Associates, Inc. The reports which are applicable to the entire site, including all of the Planning Areas, are summarized below: Geotechnical Investigation, Proposed Business Park, Bressi Ranch Lots 10 - 13, Planning Area 3, Carlsbad, California; prepared for Ascent Biltmore, LLC by Southern California Geotechnical, Inc., dated December 19, 2006, Project No. 06G252-1. This report presents the results of our previous geotechnical investigation of the subject site. The work documented by this report occurred during the period of December 1, 2006 through December 19, 2006. This report states that fifteen (15) borings were drilled within the site to a depth of 19Y2± feet. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County Department of Environmental Health (DEH). The borings identified engineering fill soils extending to depths of 11/2 to 121/2± feet below existing grade. Below the fill soils, Santiago Formation bedrock materials were observed to the maximum depth explored of 191h± feet below ground surface. Groundwater was reportedly not encountered in any of the borings. The report identified corrective grading removals of shallow bedrock for the twelve building pad areas on the order of 3 feet below existing grade and to a depth of 3 feet below proposed pad grade. In addition, the depth of overexcavation was recommended to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations for the selected buildings. Geotechnical Investigation, Proposed Business Park, Bressi Ranch Lots 10 - 13, Planning Area 3, Carlsbad. California; prepared for St. Croix Capital by Southern California Geotechnical, Inc., dated November 16, 2005, Project No. 05G273-1. This report presents the results of our previous geotechnical investigation of the subject site. The work documented by this report occurred during the period of October 31, 2005 through November 16, 2005. This report states that eight (8) borings were drilled within the site to depths ranging from 10 to 191/2± feet. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County Department of Environmental Health (DEH). The borings identified engineering fill soils extending to depths of 2 to 21/2± feet below existing grade. Below the fill soils, Santiago Formation bedrock materials were observed to the maximum depth explored of 191/2± feet below ground surface. Groundwater was reportedly not encountered in any of the borings. The report identified corrective grading removals of shallow bedrock for the two building pad areas on the order of 3 feet below existing grade and to a depth of 3 feet below proposed pad grade. In addition, the depth of overexcavation was recommended to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations for the selected buildings. Geotechnical Investigation, Bressi Ranch Corporate Center, Planning Areas 1 through 5, SEC of Palomar Airport Road and El Camino Real, Carlsbad, California; prepared for Sares Regis Group by Southern California Geotechnical, Inc., dated May 3, 2004, Project No. 03G259-2. This report presents the results of our geotechnical investigation of Planning Areas 1 through 5 subsequent to the mass grading. Subsurface exploration performed as part of this geotechnical CALIFORNIA Project No. 07G227-1 SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA Page 5 CEOTECHN1CA investigation included twenty (20) borings advanced to depths of 5 to 191/2± feet below currently existing site grades. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County Department of Environmental Health (DEH). Based on the subsurface conditions, the site is underlain by recently placed compacted fill soils and sandstone and claystone bedrock. The fill soils extend to depths of up to 90± feet and were placed under the purview of a geotechnical engineer. The existing fill soils and bedrock possesses relatively high strengths, and highly variable expansive potentials. Based on the variable expansive potentials and differing strengths of the engineered fill and bedrock, and in order to provide for a new layer of structural fill that will help mitigate the potential cut/fill transitions, it was recommended that remedial grading be performed within the proposed building pad areas. The building pad areas were recommended to be overexcavated to a depth of at least 5 feet below existing grade and to a depth of at least 4 feet below proposed pad grade. The depth of overexcavation should be sufficient to provide at (east 3 feet of new structural fill beneath the bearing grade of all foundations. Supplemental Geotechnical Investigation for Mass Grading, Bressi Ranch, Carlsbad, California, prepared for Lennar Homes by Leighton and Associates, Inc., dated March 14, 2001, Project No. 971009-005. This report presents the results of a supplemental geotechnical investigation to update their earlier preliminary geotechnical report prepared in 1997. Subsurface exploration performed as part of the supplemental geotechnical investigation included eight (8) large diameter borings and fifty-six (56) exploratory trenches. Logs of these supplemental borings and trenches as well as previous work by Leighton and others is included in the report and summarized on the Geotechnical Map Included therein. Based on the presented information, the subject site is primarily underlain by sandstone bedrock. The bedrock is indicated to consist of the Tertiary age Santiago formation, which is described as massively bedded sandstone with some zones of claystone and siltstone. Some minor areas of shallow undocumented fill, terrace deposits, and alluvial/colluvial soils were also mapped within the boundaries of the subject site. Although the majority of the mapped, larger ancient landslides are located outside the boundaries of the subject site, two (2) small ancient landslides were mapped on the subject site, east of PA-1 and PA-2. Due to their small scale, they were recommended to be removed in their entirety and replaced as compacted fill. Remedial grading recommendations contained in this report indicate that all undocumented fill and alluvia l/colluvial soils should be completely removed to competent material. SuoDlemental Geotechnical Landslide Investigation, Planning Areas PA-1, PA-2, and PA- 10 through PA-12, Bressi Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton and Associates, Inc., dated February 12, 2003, Project No. 971009-007. CALIFORNIA Project No. 07G227-1 SOUTHERN BressiRanch, Lots 10-13 - Carlsbad, CA Page 6 _CE9Jg[JjçL This report presents the results of a supplemental geotechnical landslide investigation for specific portions of the site. Subsurface exploration performed as part of the supplemental geotechnical landslide investigation included nine (9) large diameter borings and five (5) exploratory trenches in the areas of the previously mapped ancient landslides. Logs of these additional borings and trenches as well as revised cross sections are included in the report. The area of the subject site addressed by this report includes the eastern portion of planning areas PA-1 and PA-2 where several nested ancient landslides were mapped. Cross Sections E-E' and P-P' depict the mapped geologic conditions and the recommended remedial grading, which consisted of complete removal of the landslides and replacement as engineered fill. This report restates the previous remedial grading recommendations and provides slope stability calculations to justify the proposed grading configurations. Geotechnical Recommendations Concerning 95 Percent Relative Compaction of Fill Deeper than 40 Feet, Bressi Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton and Associates, Inc., dated February 13, 2003, Project No. 971009-007. This report addresses the settlement potential of deep fill areas and provides recommendations to reduce the time period for the majority of the settlement to occur. In several areas of the overall project, fills up to 40 to 50± feet in thickness were planned to achieve the design grades. Deep fill areas on the subject site are located in the eastern portion of PA-2, and two small areas within PA-3 and PA-5. The report recommends that all structural fills below a depth of 40 feet from finish grade be compacted to at least 95 percent of the ASTM D-1557 maximum dry density, and estimates that the time period for the majority of the settlement to occur will be reduced from 6 to 12 months to 3 to 8+ months. Near surface settlement monuments were recommended to be installed immediately after rough grading, with survey intervals of once a week for the first month, then twice a month for 3 months, and then monthly to determine completion primary settlement of deep fills. The recommended locations of the near surface settlement monuments are indicated to be contained on an index map within this report, however, the copy provided to us does not contain this plan. Summary of the As-Graded Geotechnical Conditions and Partial Completion of Rough and Fine Grading, Planning Areas PA-1 Through PA-5, Bressi Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton and Associates, Inc., dated January 20, 2004, Project No. 971009-014. This summary report indicates that grading of Planning Areas PA-1 through PA-3 is essentially complete, and that grading is ongoing in Planning Areas PA-4 and PA-5. Grading operations were reportedly performed in general accordance with the recommendations presented in Leighton's previous geotechnical reports. Geotechnical issues presented in this summary report which were not discussed in the previous reports include the presence of inactive faults within PA-4 and PA-5, perched groundwater within the overexcavated tributary canyons on the east side of PA-1 and PA-2, oversize materials within the engineered fills, high to very high expansive soils at or near finish grade, and some severe sulfate concentrations which would require the use of specialized concrete mix designs. CALIFORNIA Page No. 07(3227-1 SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA Page 7 GEOTECHNICAL As Graded Report of Mass Grading, Planning Areas PA-1, PA-2, and PA-3, Metropolitan Street, and a Portion of Town Garden Road, Gateway Road, and Alicante Road, Carlsbad Tract No. 00-06, Bressi Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton and Associates, Inc., dated April 15, 2004, Project No. 971009-014 This report documents the mass grading of Planning Areas PA-1, PA-2, and PA-3 as well as a portion of the interior streets. Most of the information contained in this report was presented in the January 20, 2004 summary report. The conclusions and recommendations are also similar to the previous report. With respect to the deep fills on this portion of the site, Leighton concluded that most of the anticipated settlement is complete, but the seven settlement monuments should be continued to be monitored. Soluble sulfate test results range from negligible to severe, and expansion index test results range from low (El = 46) to very high (El = 163). Preliminary pavement sections are presented and are based on assumed R-value of 12. Maximum cuts and fills within Planning Areas PA-1, PA-2, and PA-3 are documented as 25 and 90 feet, respectively. Fill soils below a depth of 40 feet were compacted to at least 95% of ASTM 1557 maximum dry density. Addendum to As-Graded Reports of Mass Grading Concerning the Completion of Settlement Monitoring, Planning Areas PA-1 through PA-5, Bressi Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton and Associates, Inc., dated October 11, 2004, Project No. 971009-014 This report presents the data collected from the settlement monitoring program for the deep fill (greater than 40 feet) areas of the entire site. The settlement monitoring data was collected over a period of 5 to 6 months. Based on the collected data, Leighton concludes that the primary settlement of the fill soils is essentially complete, and that construction of improvements within Planning Areas PA-1 through PA-5 may begin. Secondary consolidation settlement of deep fills is estimated to be less than 1 to 3 inches depending on the depth of fill. Differential settlements are estimated to be on the order of 1/2 inch in 25 feet. CALIFORNIA Project No. 07G227-1 SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA - _. PTcI.cL Page 8 4.0 SUBSURFACE EXPLORATION 4.1 Scope of Exploration/Sampling Methods The subsurface exploration conducted for this project consisted of eight (8) borings advanced to depths of 191/2± feet below currently existing site grades. The maximum depth of our borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County Department of Environmental Health (DEH). All of the borings were logged during excavation by a member of our staff. Representative bulk and in-situ soil samples were taken during drilling. Relatively undisturbed in-situ samples were taken with a split barrel "California Sampler" containing a series of one inch long, 2.416± inch diameter brass rings. This sampling method is described in ASTM Test Method D-3550. In-situ samples were also taken using a 1.4± inch inside diameter split spoon sampler, in general accordance with ASTM D-1586. Both of these samplers are driven into the ground with successive blows of a 140-pound weight falling 30 inches. The blow counts obtained during driving are recorded for further analysis. Bulk samples were taken at periodic locations in the trenches. The bulk samples were collected in plastic bags to retain their original moisture content. The relatively undisturbed ring samples were placed in molded plastic sleeves that were then sealed and transported to our laboratory. The approximate locations of the borings are indicated on the Boring Location Plan, included as Plate 2 of this report. The Boring Logs, which illustrate the conditions encountered at the boring locations, as well as some of the results of the laboratory testing, are included in Appendix B. 4.2 Geotechnical Conditions Presented below is a generalized summary of the subsurface conditions encountered at the boring locations. More detailed descriptions of the conditions encountered are illustrated on the Boring Logs, included in Appendix B. Artificial Fill Artificial fill soils were encountered at the ground surface at many of the boring locations. These fill soils extend to depths of up to 8± feet below existing grade. As previously discussed, the fill soils within other areas of PA-3 are documented to have maximum depths of 40 to 50± feet. The fill soils encountered in the borings generally consist of medium dense fine sands and clayey fine sands. The fill soils possess moderately high strengths, moisture contents near or above optimum and based on their color mottling and composition, appeared to be well mixed. CALIFORNIA Project No. 07G227-1 SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA -- Page 9 Bedrock Bedrock was encountered at or near ground surface or beneath the fill soils at all of the boring locations. The bedrock encountered at this site consists of Tertiary age Santiago formation, which is comprised of dense to very dense sandstone with some zones of claystone and siltstone. Bedding within the Santiago formation on site is generally massive with no significant planes of weakness or discontinuities. The sandstone unit is typically light gray in color, contains moderate iron oxide staining, and is comprised of weakly cemented silty fine sand. The siltstone unit is typically light gray to gray in color, contains moderate iron oxide staining, and is comprised of fine sandy silt. The claystone unit is typically dark gray to gray green in color, contains some shell fragments, gypsum veins, and is comprised of silts and clays. Groundwater Based on the water level measurements, and the moisture contents of the recovered soil samples, the static groundwater table is considered to have existed at a depth in excess of 20± feet at the time of the subsurface exploration. Further, based on the conditions documented in the mass grading report by Leighton, no groundwater was encountered during grading. Therefore, groundwater is expected to be at depths greater than the extent of the fill soils, which are 40 to 50± feet thick within PA-3. 4.3 Geologic Conditions Geologic research indicates that the site is underlain by sandstone mapped as the Santiago Formation (Map Symbol isa) with nearly horizontal bedding attitudes. The primary available reference applicable to the subject site is DMG Open-File Report 96-02, Geologic Map of the Northwestern Part of San Diego County. California, by California Division of Mines and Geology, 1996. Based on the materials encountered in the exploratory borings, it Is our opinion the site Is underlain by sandstone, siltstone and claystone bedrock consisting of the Santiago formation (Map Symbol isa). The bedrock encountered in the exploratory borings and observed at the ground surface is generally massively bedded and the structure is comprised of nearly horizontal bedding with some moderately developed joints in the upper, less weathered portions of the bedrock. CALIFORNIA Bressi Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 SOUTHERN Page 10 - GEOTECHNICAL 5.0 LABORATORY TESTING The soil samples recovered from the subsurface exploration were returned to our laboratory for further testing to determine selected physical and engineering properties of the soils. The tests are briefly discussed below. It should be noted that the test results are specific to the actual samples tested, and variations could be expected at other locations and depths. Classification All recovered soil samples were classified using the Unified Soil Classification System (USCS), in accordance with ASTM D-2488. Field identifications were then supplemented with additional visual classifications and/or by laboratory testing. The USCS classifications are shown on the Boring Logs and are periodically referenced throughout this report. In-situ Density and Moisture Content The density has been determined for selected relatively undisturbed ring samples. These densities were determined in general accordance with the method presented in ASTM D-2937. The results are recorded as dry unit weight in pounds per cubic foot. The moisture contents are determined in accordance with ASTM D-2216, and are expressed as a percentage of the dry weight. These test results are presented on the Boring Logs. Consolidation Selected soil samples have been tested to determine their consolidation potential, in accordance with ASTM D-2435. The testing apparatus is designed to accept either natural or remolded samples in a one-inch high ring, approximately 2.416 inches in diameter. Each sample is then loaded incrementally In a geometric progression and the resulting deflection is recorded at selected time intervals. Porous stones are in contact with the top and bottom of the sample to permit the addition or release of pore water. The samples are typically inundated with water at an intermediate load to determine their potential for collapse or heave. The results of the consolidation testing are plotted on Plates C-i through C-B in Appendix C of this report. Expansion Index The expansion potential of the on-site soils was determined in general accordance with Uniform Building Code (UBC) Standard 18-2. The testing apparatus is designed to accept a 4-inch diameter, 1-in high, remolded sample. The sample is initially remolded to 50 ± 1 percent saturation and then loaded with a surcharge equivalent to 144 pounds per square foot. The sample is then inundated with water, and allowed to swell against the surcharge. The resultant swell or consolidation is recorded after a 24-hour period. The results of the El testing are as follows: CALIFORNIA Page Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 SOUTHERN - Page 11 Sample Identification Expansion Index Expansive Potential B-5@Oto5feet 54 Medium Soluble Sulfates Representative samples of the near-surface soils have been submitted to a subcontracted analytical laboratory for determination of soluble sulfate content. Soluble sulfates are naturally present in soils, and if the concentration is high enough, can result in degradation of concrete which comes into contact with these soils. The results of the soluble sulfate testing are not yet available. These test results, along with recommendations for any appropriate sulfate resistant concrete mix designs will be presented in an addendum report. CALIFORNIA Bressi Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 SOUTHERN Page 12 6.0 CONCLUSIONS AND RECOMMENDATIONS Based on the results of our review, field exploration, laboratory testing and geotechnical analysis, the proposed development is considered feasible from a geotechnical standpoint. The recommendations contained in this report should be taken into the design, construction, and grading considerations. The recommendations are contingent upon all grading and foundation construction activities being monitored by the geotechnical engineer of record. The Grading Guide Specifications, included as Appendix D, should be considered part of this report, and should be incorporated into the project specifications. The contractor and/or owner of the development should bring to the attention of the geotechnical engineer any conditions that differ from those stated in this report, or which may be detrimental for the development. Following completion of the recommended grading and foundation construction procedures, the subject site is considered suitable for its intended use. 6.1 Seismic Design Considerations The subject site is located in an area which is subject to strong ground motions due to earthquakes. The completion of a site specific seismic hazards analysis is beyond the scope of services for this geotechnical investigation. However, it should be noted that numerous faults capable of producing significant ground motions are located near the subject site. Due to economic considerations, it is not generally considered reasonable to design a structure that is not susceptible to earthquake damage. Therefore, significant damage to structures may be unavoidable during large earthquakes. The proposed structures should, however, be designed to resist structural collapse and thereby provide reasonable protection from serious injury, catastrophic property damage and loss of life. Faulting and Seismicity Research of available maps indicates that the subject site is not located within an Alquist-Priolo Earthquake Fault Zone. Therefore, the possibility of significant fault rupture on the site is considered to be low. Seismic Design Parameters Based on standards in place at the time of this report, the proposed development must be designed in accordance with the requirements of the latest edition of the 2007 California Building Code (CBC), which is based on the 2006 International Building Code (IBC). The IBC provides procedures for earthquake resistant structural design that Include considerations for on-site soil conditions, occupancy, and the configuration of the structure including the structural system and height. The seismic design parameters presented below are based on the, soil profile, and the proximity of known faults with respect to the subject site. CALIFORNIA Bressi Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 SOUTHERN - - - Page 13 GEoTEcHNIcAL The 2006 IBC Seismic Design Parameters have been generated using Earthquake Ground Motion Parameters, a software application developed by the United States Geological Survey. This software application, available at the USGS web site calculates seismic design parameters in accordance with the 2006 IBC, utilizing a database of deterministic site accelerations at 0.01 degree intervals. The table below is a compilation of the data provided by the USGS application. A copy of the output generated from this program is included in Appendix E of this report. A copy of the Design Response Spectrum, as generated by the USGS application is also included in Appendix E. Based on this output, the following parameters may be utilized for the subject site: 2006 [BC SEISMIC DESIGN PARAMETERS Parameter Value Mapped Spectral Acceleration at 0.2 sec Period Ss 1.794 Mapped Spectral Acceleration at 1.0 sec Period S1 0.667 Site Class --- D Short-Period Site Coefficient at 0.2 sec Period Fa 1.0 Long-Period Site Coefficient at 1.0 sec Period F 1.5 Site Modified Spectral Acceleration at 0.2 sec Period SMS 1.794 Site Modified Spectral Acceleration at 1.0 sec Period SM1 1.0 Design Spectral Acceleration at 0.2 sec Period SDS 1.196 Design Spectral Acceleration at 1.0 sec Period SDI 0.667 Liquefaction Liquefaction is the loss of strength in generally cohesionless, saturated soils when the pore- water pressure induced In the soil by a seismic event becomes equal to or exceeds the overburden pressure. The primary factors which influence the potential for liquefaction include groundwater table elevation, soil type and grain size characteristics, relative density of the soil, initial confining pressure, and intensity and duration of ground shaking. The depth within which the occurrence of liquefaction may impact surface improvements is generally identified as the upper 50 feet below the existing ground surface. Liquefaction potential is greater in saturated, loose, poorly graded fine sands with a mean (d50) grain size in the range of 0.075 to 0.2 mm (Seed and Idriss, 1971). Clayey (cohesive) soils or soils which possess clay particles (d<0.005mm) in excess of 20 percent (Seed and Idriss, 1982) are generally not considered to be susceptible to liquefaction, nor are those soils which are above the historic static groundwater table. The subsurface conditions encountered at the subject site are not conducive to liquefaction. These conditions consist of compacted fill soils underlain by high strength sandstone and claystone bedrock, which is not susceptible to earthquake-induced liquefaction. Based on the subsurface conditions, liquefaction is not considered to be a significant design concern for this project. SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA CALIFORNIA Project No. 07G227-1 Page 14 6.2 Geotechnical Design Considerations General The subject site is underlain by fill soils and by sandstone and occasional siltstone and claystone bedrock. The fill soils, extending to maximum depths of up to 8± within the subject site generally 'consist of moderate strength sands, sIlty sands and clayey sands. Laboratory testing indicates that these materials possess generally favorable consolidation and collapse characteristics. However, several cut/fill transitions between the fill and bedrock were created by the mass grading procedures. More importantly, the proposed grading to establish the new finished floor, elevations is expected to result In the formation of additional cut/fill transitions. The resultant subsurface profile is expected to provide variable support characteristics for the foundations of the proposed structures. Based on these considerations, it Is recommended that remedial grading be performed within the new building areas in order to provide a subgrade suitable for support of the foundations and floor slabs of the new structures. The primary geotechnical design consideration that will impact the proposed development is the fact that the proposed grading will create cut/fill transitions within some of the proposed building areas. These considerations are discussed in detail in the following sections of this report. Grading and Foundation Plan Review The conclusions and recommendations presented in this report are based on the preliminary plans provided to our office. No grading plans were available at the time of this report. Once preliminary grading plans become available, it is recommended that they be provided to our office for review with regard to the conclusions and recommendations presented herein. In addition, a foundation plan was not available at the time of this report. It is recommended that preliminary foundation plans be provided to our office once they become available. Depending on the results of our review, some modifications to the recommendations contained in this report may be warranted. Settlement The results of the consolidation/collapse testing indicate that the existing fill soils are not subject to significant collapse upon moisture infiltration. In addition, the existing fill soils do not exhibit significant consolidation when exposed to load increases in the range of those that will be imposed by the new foundations. Provided that the recommendations contained within this report are implemented in the structural design and construction of the proposed buildings, the post-construction settlements are expected to be within tolerable limits. Following completion of the recommended grading, the post-construction static settlements are expected to be within tolerable limits. Cut/Fill Transitions Both buildings are closely underlain by dense bedrock. It is expected that cuts and fills of up to 1 to 3± will be necessary within these building areas to achieve the proposed subgrade Project No. 07G227-1 CALIFORNIA SOUTHERN ' Bressi Ranch, Lots 10-13 - Carlsbad, CA Page 15 elevations. Therefore, cut/fill transitions are expected to exist within these building areas after completion of the proposed grading. This cut/fill transition condition at bearing grade raises a potential for additional differential settlement. This report contains recommendations for additional remedial grading within these building pads to remove this geologic and cut/fill transition. It should be noted that the extent of areas that will require overexcavation to mitigate cut/till transitions will depend upon the final grades that are established throughout the site. Therefore, the extent of this remedial grading may change, following our review of the preliminary grading plan. Expansion Most of the on-site soils consist of medium expansive soils and bedrock (El = 54). Based on the presence of expansive soils, special care should be taken to properly moisture condition and maintain adequate moisture content within all subgrade soils as well as newly placed fill soils. The foundation and floor slab design recommendations contained within this report are made in consideration of the expansion index test results. It is expected that significant blending of the on-site soils will occur during precise grading procedures, and that the resulting building pad subgrade soils will possess medium expansion potentials. It is recommended that additional expansion index testing be conducted at the completion of precise grading to verify the expansion potential of the as-graded building pads. Shrinkage/Subsidence Based on our experience with the on-site soils and rock materials, removal and recompaction of the existing near-surface engineered fill soils is estimated to result in average shrinkage or bulking of less than 5 percent. Where the existing bedrock is overexcavated and replaced as structural fill, bulking on the order of 0 to 5 percent is expected. Minor ground subsidence is expected to occur in the soils below the zone of removal due to settlement and machinery working. The subsidence is estimated to be 0.1 feet. These estimates may be used for grading in areas that are underlain by existing engineered fill soils. No significant subsidence will occur in areas that are immediately underlain by sandstone bedrock. These estimates are based on previous experience and the subsurface conditions encountered at the boring locations. The actual amount of subsidence is expected to be variable and will be dependant on the type of machinery used, repetitions of use, and dynamic effects, all of which are difficult to assess precisely. Setbacks In accordance with Uniform Building Code (UBC) requirements, all footings should maintain a minimum horizontal setback of H/3, where H equals the slope height, measured from the outside face of the footing to any descending slope face. This setback should not be less than 7 feet, nor need it be greater than 40 feet. CALIFORNIA Project No. 07G227-1 SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA Page 16 GEOTECHNICAL 6.3 Site Grading Recommendations The grading recommendations presented below are based on the subsurface conditions encountered at the boring locations and our understanding of the proposed development. We recommend that all grading activities be completed in accordance with the Grading Guide Specifications included as Appendix D of this report, unless superseded by site specific recommendations presented below. Site Stripping and Demolition Initial site preparation should include stripping of any vegetation and organic debris. Based on conditions observed at the time of the subsurface exploration, moderate stripping of native grass and weeds is expected to be necessary. Initial grading operations should also include abandonment of the existing desilting basins, located throughout the site. Any softened soils, silt deposits, water, or other unsuitable materials should be removed from the detention basin. Removals should extend to a depth of suitable structural compacted fill soils or bedrock. Where the detention basins are located within proposed building areas, the building pad overexcavation recommendations should also be implemented. Treatment of Existing Soils: Building Pads Remedial grading will be necessary in several of the building areas to mitigate potential variable support conditions due to cut/fill transitions that will exist at or near the proposed foundation bearing grade. Remedial grading should be performed within both building areas to remove and replace a portion of the dense bedrock as engineered fill. The existing bedrock should be overexcavated to provide for a new layer of compacted structural fill, extending to a depth of at least 3 feet below proposed foundation bearing grade, throughout the building areas. Based on conditions encountered at the boring locations, it is expected that such overexcavation will be required throughout both buildings. In general, the overexcavations should extend at least 5 feet beyond the building perimeters. If the proposed structures incorporate any exterior columns (such as for a canopy or overhang) the area of overexcavation should also encompass these areas. Within areas of the proposed structures that do not require overexcavation per the recommendations presented above, it is recommended that the existing fills be overexcavated to a depth of at least 1 foot below existing grade, to remove any existing weathered and/or softened fill soils, as well as to prepare the subgrade for new fill placement. Following completion of the overexcavations, the subgrade soils (or bedrock) within the building areas should be evaluated by the geotechnical engineer to verify their suitability to serve as the structural fill subgrade, as well as to support the foundation loads of the new structure. This CALIFORNIA Project No. 07G227-1 SOUTHERN Bressi Ranch, Lo 10-13 - Carlsbad, CA - cQIEcHN1CAL Page 17 evaluation should include proofrolling with a heavy rubber-tired vehicle to identify any soft, loose or otherwise unstable soils that must be removed. Some localized areas of deeper excavation may be required if loose, porous, or low density soils are encountered at the bottom of the overexcavation. The exposed subgrade soils should then be scarified to a depth of 12 inches, moisture conditioned to 2 to 4 percent above optimum moisture content, and recompacted. Treatment of Existing Soils: Retaining Walls and Site Walls The existing soils within the areas of any proposed retaining walls underlain by less than 2 feet of existing engineered fill soils should be overexcavated to a depth of 2 feet below foundation bearing grade and replaced as compacted structural fill, as discussed above for the proposed building pad. Subgrade soils in areas of non-retaining site walls should be overexcavated to a depth of 1 foot below proposed bearing grade, if not underlain by at lest 1 foot of existing engineered fill soils. In both cases, the overexcavation subgrade soils should be evaluated by the geotechnical engineer prior to scarifying, moisture conditioning and recompacting the upper 12 inches of exposed subgrade soils. In areas where unsuitable fill soils are encountered at foundation subgrade level, additional overexcavation or deepened footings will be necessary. The previously excavated soils may then be replaced as compacted structural fill. Treatment of Existing Soils: Parking Areas Overexcavation of the existing fill soils in the new parking areas is generally not considered warranted, with the exception of any areas where lower strength soils are identified by the geotechnical engineer during grading. Subgrade preparation in the remaining new parking areas should initially consist of completion of cuts where required. The geotechnical engineer should then evaluate the subgrade to Identify any areas of unsuitable soils. Based on conditions observed at the site at the time of drilling, no significant overexcavation is expected to be necessary within the new parking areas. The subgrade soils should then be scarified to a depth of 12± inches, moisture conditioned to 2 to 4± percent above optimum, and recompacted to at least 90 percent of the ASTM D-1557 maximum dry density. Depending upon the actual finished grades, which have not yet been established, portions of the parking lot subgrades may be immediately underlain by bedrock. These materials may be used for direct pavement subgrade support. However, the owner and/or developer of the project should understand that minor amounts of reflective cracking and/or minor differential movements should be expected to occur near the location of the transitions between these bedrock materials and the adjacent engineered fill. If such cracking or minor differential movements within the pavements is not considered acceptable, additional overexcavation should be performed within the cut portions of the parking areas. Fill Placement Fill soils should be placed in thin (6± inches), near-horizontal lifts, moisture conditioned to 2 to 4 percent above optimum moisture content, and compacted. SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 CALIFORNIA Page 18 cEoTEcHNIcAL On-site soils may be used for fill provided they are cleaned of any debris or oversized materials to the satisfaction of the geotechnical engineer. All grading and fill placement activities should be completed in accordance with the requirements of the Uniform Building Code and the grading code of the City of Carlsbad. All fill soils should be compacted to at least 90 percent of the ASTM D-1557 maximum dry density. Fill soils should be well mixed. Compaction tests should be performed periodically by the geotechnical engineer as random verification of compaction and moisture content. These tests are intended to aid the contractor. Since the tests are taken at discrete locations and depths, they may not be indicative of the entire fill and therefore should not relieve the contractor of his responsibility to meet the job specifications. Imported Structural Fill All imported structural fill should consist of low expansive (El < 30), well graded soils possessing at least 10 percent fines (that portion of the sample passing the No. 200 sieve). Additional specifications for structural fill are presented in the Grading Guide Specifications, included as Appendix D. Utility Trench Backfill In general, all utility trench backfill should be compacted to at least 90 percent of the ASTM D- 1557 maximum dry density. As an alternative, a clean sand (minimum Sand Equivalent of 30) may be placed within trenches and flooded in place. Compacted trench backfill should conform to the requirements of the local grading code, and more restrictive requirements may be indicated by the City of Carlsbad. Materials used to backfill trenches should consist of well graded granular soils with a maximum particle size of 3 inches. All utility trench backfihls should be witnessed by the geotechnical engineer. The trench backfill soils should be compaction tested where possible; probed and visually evaluated elsewhere. Utility trenches which parallel a footing, and extending below a lh:lv plane projected from the outside edge of the footing should be backfllled with structural fill soils, compacted to at least 90 percent of the ASTM D-1557 standard. Sand or pea gravel backfill, unless it is similar to the native soils, should not be used for these trenches. 6.4 Construction Considerations Moisture Sensitive Subgrade Soils Some of the near surface soils possess appreciable silt and clay content and may become unstable if exposed to significant moisture infiltration or disturbance by construction traffic. In addition, based on their granular content, the on-site soils will also be susceptible to erosion. The site should, therefore, be graded to prevent ponding of surface water and to prevent water from running into excavations. CALIFORNIA Project No. 07G227-1 SOUTHERN Bress Ranch, Lots 10-13 - Carlsbad, CA Page 19 GEOTECHNICAL Excavation Considerations Based on conditions encountered at the boring locations, the bedrock that underlies the subject site possesses a dense to very dense relative density, but is somewhat friable. It is expected that it will be feasible to utilize conventional grading equipment within the depths that were explored by the borings. However, some difficulty may be encountered during excavation, possibly requiring large single shank-equipped bulldozers, excavators, etc. The grading contractor should verify the need for special excavation equipment prior to bidding the project. Based on the presence of moderate granular content of the soils throughout the development area, minor to moderate caving of shallow excavations may occur. Flattened excavation slopes may be sufficient to mitigate caving of shallow excavations, although deeper excavations may require some form of external stabilization such as shoring or bracing. Temporary excavation slopes should be no steeper than lh:lv. All excavation activities on this site should be conducted in accordance with Cal-OSHA regulations. Expansive Soils As previously discussed, the on site soils have been determined to possess a medium expansion potential. Therefore, care should be given to proper moisture conditioning of all building pad subgrade soils to a moisture content of 2 to 4 percent above the Modified Proctor optimum during site grading. All imported fill soils should have low to medium expansive characteristics. In addition to adequately moisture conditioning the subgrade soils and fill soils during grading, special care must be taken to maintain the moisture content of these soils at 2 to 4 percent above the Modified Proctor optimum. This will require the contractor to frequently moisture condition these soils throughout the grading process, unless grading occurs during a period of relatively wet weather. Due to the presence of expansive soils at this site, provisions should be made to limit the potential for surface water to penetrate the soils Immediately adjacent to the structures. These provisions should include directing surface runoff into rain gutters and area drains, reducing the extent of landscaped areas around the structures, and sloping the ground surface away from the buildings. Where possible, it is recommended that landscaped planters not be located immediately adjacent to the proposed buildings. If landscaped planters around the buildings are necessary, it is recommended that drought tolerant plants or a drip irrigation system be utilized, to minimize the potential for deep moisture penetration around the structure. Other provisions, as determined by the civil engineer may also be appropriate. Elevator Equipment Shafts It is expected that the proposed three story buildings will incorporate at least one elevator. Typically these elevators require installation of relatively large diameter steel pipes as part of the elevator counterweights. it is expected that the pipes will be installed within slightly oversized borings. Where these pipes are installed, the annulus between the borehole wall and the elevator pipe should be backfilled with a lean concrete slurry or grout. Placement of loose backfill soils around these pipes could result in localized settlement of the structural fill soils and/or foundation elements. CALIFORNIA Project No. 07G227-1 SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA Page 20 GEOTECIINICAL Groundwater Free water was not encountered within the depths explored by the borings drilled for this project. These borings extended to a maximum depth of 20± feet below existing grade. Based on this information, groundwater is not expected to impact the proposed grading or foundation construction activities. 6.5 Foundation Design and Construction Based on the preceding preliminary grading recommendations, it is assumed that the new building pads will be immediately underlain by existing or newly placed structural fill soils extending to depths of at least 3± feet below foundation bearing grade. Based on this subsurface profile, the proposed structures may be supported on conventional shallow foundation systems. Foundation Design Parameters New square and rectangular footings may be designed as follows: Maximum, net allowable soil bearing pressure: 2,500 lbs/ft2. The allowable bearing pressure may be increased by 1/3 when considering short duration wind or seismic loads. Minimum wall/column footing width: 14 inches/24 inches Minimum longitudinal steel reinforcement within strip footings: Four (4) No. 5 rebars (2 top and 2 bottom), due to medium expansive potential of near surface soils. Minimum foundation embedment: 12 inches into suitable structural fill soils, and at least 18 inches below adjacent exterior grade. Interior column footings may be placed immediately beneath the floor slab. It is recommended that the perimeter foundations be continuous across all exterior doorways. Flatwork adjacent to exterior doors should be doweled into the perimeter foundations in a manner determined by the structural engineer. The minimum steel reinforcement recommended above is based on geotechnical considerations. Additional reinforcement may be necessary for structural considerations. The actual design of the foundations should be determined by the structural engineer. Foundation Construction The foundation subgrade soils should be evaluated at the time of overexcavation, as discussed in Section 6.3 of this report. It Is further recommended that the foundation subgrade soils be evaluated by the geotechnical engineer immediately prior to steel or concrete placement. Soils suitable for direct foundation support should consist of newly placed structural fill, compacted to at least 90 percent of the ASTM D-1557 maximum dry density. Any unsuitable bearing , SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA CALIFORNIA Project No. 07G227-1 dll cAL Page 21 EQT materials should be removed to a depth of suitable bearing compacted structural fill, with the resulting excavations backfilled with compacted fill soils. As an alternative, lean concrete slurry (500 to 1,500 psi) may be used to backfill such isolated overexcavations. The foundation subgrade soils should also be properly moisture conditioned to 2 to 4 percent above the Modified Proctor optimum, to a depth of at least 12 inches below bearing grade. Estimated Foundation Settlements Post-construction total and differential settlements induced by the foundation loads of the new structures are estimated to be less than 1.0 and 0.5 inches, respectively, for shallow foundations designed and constructed in accordance with the recommendations provided in this report. The differential movements are expected to occur over a 30-foot span, thereby resulting in an angular distortion of less than 0.002 inches per inch. Lateral Load Resistance Lateral load resistance will be developed by a combination of friction acting at the base of foundations and slabs and the passive earth pressure developed by footings below grade. The following friction and passive pressure may be used to resist lateral forces: Passive Earth Pressure: 250 lbs/ft3 Friction Coefficient: 0.25 These are allowable values, and include a factor of safety. When combining friction and passive resistance, the passive pressure component should be reduced by one-third. These values assume that footings will be poured directly against suitable compacted structural fill. The maximum allowable passive pressure is 2500 lbs/ft2. 6.6 Floor Slab Design and Construction Subgrades which will support new floor slabs should be prepared in accordance with the recommendations contained in the Site Grading Recommendations section of this report. Based on the anticipated grading which will occur at this site, the floors of the new structures may be constructed as conventional slabs-on-grade supported on newly placed structural fill. Based on geotechnical considerations, the floor slabs may be designed as follows: Minimum slab thickness: 5 inches Minimum slab reinforcement: No. 3 bars at 18-inches on-center, in both directions. Slab underlayment: 10-mil vapor barrier, overlain by 2 inches of clean sand. Where moisture sensitive floor coverings are not anticipated, the vapor barrier and 2-inch layer of sand may be eliminated. 4. . SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA CALIFORNIA Project No. 07G227-1 Page 22 r cEOTEcINIcA l. Moisture condition the floor slab subgrade soils to 2 to 4 percent above optimum moisture content, to a depth of 12 inches. Proper concrete curing techniques should be utilized to reduce the potential for slab curling or the formation of excessive shrinkage cracks. 6.7 Retaining Wall Design Recommendations It is expected that some small retaining walls may be required to facilitate the new site grades. The parameters recommended for use in the design of these walls are presented below. Retaining Wall Design Parameters Based on the soil conditions encountered at the boring locations, the following parameters may be used in the design of new retaining walls for this site. We have provided parameters for two different types of wall backfill: on-site soils consisting of silty sands and clayey sands; and imported select granular material. In order to use the design parameters for the imported select fill, this material must be placed within the entire active failure wedge. This wedge is defined as extending from the base of the retaining wall upwards at a 59 degree angle of inclination. RETAINING WALL DESIGN PARAMETERS Soil T roe Design Parameter Imported On-Site Aggregate Base Silty Sands and Clayey Sands Internal Friction Angle (4)) 380 280 Unit Weight 130 lbs/ft3 125 lbs/ft3 Active Condition (level backfill) 31 lbs/ft3 45 lbs/ft3 Equivalent Fluid Active Condition Pressure: (2h:lv backfill) 44 lbs/ft3 79 lbs/ft3 At-Rest Condition (level backfill) 48 lbs/ft3 66 lbs/ft3 Regardless of the backfill type, the walls should be designed using a soil-footing coefficient of friction of 0.25 and an equivalent passive pressure of 250 lbs/ft3. The active earth pressures may be used for the design of retaining walls which do not directly support structures or support soils which in turn support structures and which will be allowed to deflect. The at-rest earth pressures should be used for walls which will not be allowed to deflect such as those which will support foundation bearing soils, or which will support foundation loads directly. CALIFORNIA Bressi Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 SOUTHERN - - Page 23 Where the soils on the toe side of the retaining wall are not covered by a "hard surface such as a structure or pavement, the upper 1 foot of soil should be neglected when calculating passive resistance due to the potential for the material to become disturbed or degraded during the life of the structure. Retaining Wall Foundation Design Retaining walls should be supported within newly placed structural fill monitored during placement by the geotechnical engineer. Where retaining walls are also serving as building walls, they should be graded in accordance with the recommendations presented in Section 6.3 of this report for the proposed building pad areas. Foundations to support new retaining walls should be designed in accordance with the general Foundation Design Parameters presented in a previous section of this report. Backfill Material It is recommended that a minimum 1 foot thick layer of free-draining granular material (less than 5 percent passing the No. 200 sieve) should be placed against the face of the retaining walls. This material should be approved by the geotechnical engineer. A suitable geotextile should be used to separate the layer of free draining granular material from the backfill soils. If the layer of free-draining material is not covered by an impermeable surface, such as a structure or pavement, a 12-Inch thick layer of a low permeability soil should be placed over the backfill to reduce surface water migration to the underlying soils. All retaining wall backfill should be placed and compacted under engineering controlled conditions in the necessary layer thicknesses to ensure an in-place density between 90 and 93 percent of the maximum dry density as determined by the Modified Proctor test (ASTM D1557- 91). Care should be taken to avoid over-compaction of the soils behind the retaining walls, and the use of heavy compaction equipment should be avoided. Subsurface Drainage As previously indicated, the retaining wall design parameters are based upon drained backfill conditions. Consequently, some form of permanent drainage system will be necessary in conjunction with the appropriate backfill material. Subsurface drainage may consist of either: A weep hole drainage system typically consisting of a series of 4-inch diameter holes in the wall situated slightly above the ground surface elevation on the exposed side of the wall and at an approximate 8-foot on-center spacing. The weep holes should include a minimum 2 cubic foot gravel pocket surrounded by an appropriate geotextile fabric at each weep hole location. A 4-inch diameter perforated pipe surrounded by 2 cubic feet of gravel per linear foot of drain placed behind the retaining wall, above the footing. The gravel drain should be wrapped in a suitable geotextile fabric to reduce the potential for migration of fines. The footing drain should be extended to daylight or tied into a storm drainage system. CALIFORNIA Project No 07G227-1 SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA -. Page 24 GEOTECHNICAL 68 Pavement Design Parameters Site preparation in the pavement area should be completed as previously recommended in the Site Grading Recommendations section of this report. The subsequent preliminary pavement recommendations assume proper drainage and construction monitoring, and are based on either PCA or CALTRANS design parameters for a twenty (20) year design period. These preliminary designs also assume a routine pavement maintenance program to obtain the 20-year pavement service life. Pavement Subcirades It is anticipated that the new pavements will be primarily supported on a layer of compacted structural fill, consisting of scarified, thoroughly moisture conditioned and recompacted native materials and/or fill soils. The on-site soils generally consist of sandy clays and sandy clays. These soils are considered to possess fair pavement support characteristics with R-values of 10 to 20. Since R-value testing was not included in the scope of services for this project, the subsequent pavement design is based upon an assumed R-value of 15. Any fill material imported to the site should have support characteristics equal to or greater than that of the on-site soils and be placed and compacted under engineering controlled conditions. It is recommended that R-value testing be performed after completion of rough grading. Depending upon the results of the R-value testing, it may be feasible to use thinner pavement sections in some areas of the site. Asphaltic Concrete The pavement designs are based on the traffic indices M's) indicated. The client and/or civil engineer should verify that these li's are representative of the anticipated traffic volumes. If the client and/or civil engineer determine that the expected traffic volume will exceed those recommended herein, we should be contacted for supplementary recommendations. The design traffic indices equate to the following approximate daily traffic volumes over a 20-year design life, assuming 5 operational traffic days per week: Traffic Index No. of Heavy Trucks per Day 4.0 0 5.0 1 6.0 3 7.0 11 For the purposes of the traffic volumes above, a truck is defined as a 5-axle tractor-trailer unit, with one 8-kip axle and two 32-kip tandem axles. All of the traffic indices allow for 1000 automobiles per day. Presented below are the recommended thicknesses for new flexible pavement structures consisting of asphaltic concrete over a granular base. It should be noted that the TI = 5.0 section only allows for 1 truck per day. Therefore, all significant heavy truck traffic must be excluded from areas where this thinner pavement section is used; otherwise premature pavement distress may occur. • SOUTHERN Bressi Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 CALIFORNIA Page 25 'cEoTEcHNIçAL ASPHALT PAVEMENTS Thickness (inches) Materials Auto Parking Auto Drive Light Truck Moderate = 45) Lanes Traffic Truck Traffic (TI = 5.5) (TI = 6.0) (TI = 7.0) Asphalt Concrete 4 4 4 4 Aggregate Base 5 8 10 13 Compacted Subgrade 12 12 I 12 F 12 (90% minimum compaction) The aggregate base course should be compacted to at least 95 percent of the ASTM D-1557 maximum dry density. The asphaltic concrete should be compacted to at least 95 percent of the Marshall maximum density, as determined by ASTM D-2726. The aggregate base course may consist of crushed aggregate base (CAB) or crushed miscellaneous base (CMB), which is a recycled gravel, asphalt and concrete material. The gradation, R-Value, Sand Equivalent, and Percentage Wear of the CAB or CMB should comply with appropriate specifications contained in the current edition of the "Greenbook" Standard Soecifications for Public Works Construction. Portland Cement Concrete The preparation of the subgrade soils within concrete pavement areas should be performed as previously described for proposed asphalt pavement areas. Since significant portions of the granitic bedrock are expected to be removed around the perimeters of the proposed structures where the Portland cement concrete pavements will be located, the pavement design presented below is based on the presence of existing or newly placed compacted structural fill immediately beneath the proposed pavement subgrade elevation. The minimum recommended thicknesses for the Portland Cement Concrete pavement sections are as follows: PORTLAND CEMENT CONCRETE PAVEMENTS Thickness (inches) Materials Automobile Parking Drive Lanes (TI = 5.5) and Light Truck Moderate Truck (TI = 4.5) Traffic Traffic (TI (TI = 7.0) _=_6.0) PCC 5 51/2 7 Compacted Subgrade 12 12 12 I (95% minimum compaction) I The concrete should have a 28-day compressive strength of at least 3,000 psi. Reinforcing within all pavements should consist of at least heavy welded wire mesh (6x6-W2.9xW2.9 WWF) placed at mid-height in the slab. In areas underlain by expansive soils, the reinforcement should y SOUTHERN Bressi Ranch, Lots 1043 - Carlsbad, CA Project No. 07G227-1 CALIFORNIA Page 26 be increased to No. 4 bars at 18 inches on center. The maximum joint spacing within all of the PCC pavements is recommended to be equal to or less than 30 times the pavement thickness. CALIFORNIA Bressi Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 SOUTHERN Page 27 GEOTECHNICAI 7.0 GENERAL COMMENTS This report has been prepared as an instrument of service for use by the client in order to aid in the evaluation of this property and to assist the architects and engineers in the design and preparation of the project plans and specifications. This report may be provided to the contractor(s) and other design consultants to disclose information relative to the project. However, this report is not intended to be utilized as a specification in and of itself, without appropriate interpretation by the project architect, structural engineer, arid/or civil engineer. The reproduction and distribution of this report must be authorized by the client and Southern California Geotechnical, Inc. Furthermore, any reliance on this report by an unauthorized third party is at such party's sole risk, and we accept no responsibility for damage or loss which may occur. The analysis of this site was based on a subsurface profile interpolated from limited discrete soil samples. While the materials encountered in the project area are considered to be representative of the total area, some variations should be expected between boring locations and sample depths. If the conditions encountered during construction vary significantly from those detailed herein, we should be contacted immediately to determine if the conditions alter the recommendations contained herein. This report has been based on assumed or provided characteristics of the proposed development. It is recommended that the owner, client, architect, structural engineer, and civil engineer carefully review these assumptions to ensure that they are consistent with the characteristics of the proposed development. If discrepancies exist, they should be brought to our attention to verify that they do not affect the conclusions and recommendations contained herein. We also recommend that the project plans and specifications be submitted to our office for review to verify that our recommendations have been correctly interpreted. The analysis, conclusions, and, recommendations contained within this report have been promulgated in accordance with generally accepted professional geotechnical engineering practice. No other warranty is implied or expressed. CALIFORNIA Bressi Ranch, Lots 10-13 - Carlsbad, CA Project No. 07G227-1 SOUTHERN Page 28 GEOTECHNICAL :'• ,- - , I ; -' • I l 4 in In EMU! S I I - I "t-- - 1.. 4S I) I. - 'I 2_II.I. 4 . c : 0400 A v4qw 2 I ! * l ;- '.;; 4; no I •:S.:i2. .4i S.:T:F 4 It1&: .p2 I .f 2•1.' -?-.- - 0 ',-I;'.2 . MY '- I.. - .S. y r.. 2 24 2 - -: . '1} I & / ( 1r-1S. '2 - 44 .4 •'. S 2. 2. '. . S. ', Y •'- 2. 7 ___ 0 . . -- -•- .- - A . SOURCE: SAN DIEGO COUNTY THOMAS GUIDE, 2007 OR;:ao 4k . .AITATO / 4s ,.tac000 G' o r - MCCLELLAN - PALO14R AIRPORT . - ;T T •I Acrn - '•, OL.. y • . 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BO>-.-._ . -I + PREVIOUS BORING LOCATION _._--- PROJECT NO. 06G252-1) (SCG PREVIOUS BORING LOCATION (SCG PROJECT NO. 05G273-1) - '_ ip. .• .•- .7 Afe - ENGINEERED FILL isa - SANTIAGO FORMATION - - - GEOLOGIC CONTACT - .-..,-.--- NOTE: BASE MAP PROVIDED DV SMITH CONSIATINO ARCHITECTS .--. .... :: :'f :: •:' : :•i": 11 BORING LOG LEGEND I SAMPLE TYPE GRAPHICAL I I SAMPLE DESCRIPTION SYMBOL AUGER SAMPLE COLLECTED FROM AUGER CUTTINGS, NO FIELD MEASUREMENT OF SOIL STRENGTH. I (DISTURBED) CORE ROCK CORE SAMPLE: TYPICALLY TAKEN WITH A DIAMOND-TIPPED CORE BARREL. TYPICALLY USED ONLY IN HIGHLY CONSOLIDATED BEDROCK. GRAB SOIL SAMPLE TAKEN WITH NO SPECIALIZED EQUIPMENT, SUCH AS FROM A STOCKPILE OR THE GROUND SURFACE. (DISTURBED) CALIFORNIA SAMPLER: 2-112 INCH I.D. SPLIT ________________CS BARREL SAMPLER, LINED WITH 1-INCH HIGH BRASS RINGS. DRIVEN WITH SPT HAMMER. (RELATIVELY 10 UNDISTURBED) NO RECOVER: THE SAMPLING ATTEMPT DID NOT NSR RESULT IN RECOVERY OF ANY SIGNIFICANT SOIL OR ROCK MATERIAL. SPT STANDARD PENETRATION TEST: SAMPLER IS 1.4 INCH INSIDE DIAMETER SPLIT BARREL, DRIVEN 18 INCHES WITH THE SPT HAMMER. (DISTURBED) S H SHEBLY TUBE: TAKEN WITH A THIN WALL SAMPLE TUBE, PUSHED INTO THE SOIL AND THEN EXTRACTED. (UNDISTURBED) VANE J1 VANE SHEAR TEST: SOIL STRENGH OBTAINED USING A 4 BLADED SHEAR DEVICE. TYPICALLY USED IN SOFT CLAYS-NO SAMPLE RECOVERED. COLUMN DESCRIPTIONS DEPTH: Distance in feet below the ground surface. SAMPLE: Sample Type as depicted above. BLOW COUNT: Number of blow required to advance the sampler 12 inches using a 140 lb hammer with a 30-inch drop. 50/3" indicates penetration refusal (>50 blows) at 3 inches. WH indicates that the weight of the hammer was sufficient to push the sampler 6 inches or more. POCKET PEN.: Approximate shear strength of a cohesive soil sample as measured by pocket penetrometer. GRAPHIC LOG: Graphic Soil Symbol as depicted on the following page. DRY DENSITY: Dry density of an undisturbed or relatively undisturbed sample. MOISTURE CONTENT: Moisture content of a soil sample, expressed as a percentage of the dry weight. LIQUID LIMIT: The moisture content above which a soil behaves as a liquid. PLASTIC LIMIT: The moisture content above which a soil behaves as a plastic. PASSING #200 SIEVE: The percentage of the sample finer than the #200 standard sieve. UNCONFINED SHEAR: The shear strength of a cohesive soil sample, as measured in the unconfined state. SOIL CLASSIFICATION CHART MAJOR DIVISIONS SYMBOLS TYPICAL - DESCRIPTIONS GRAPH LETTER GRAVEL AND CLEAN GRAVELS , w $ b!,blI GW WELL-GRADED GRAVELS, GRAVEL - SAND MIXTURES, LITTLE OR NO FINES GRAVELLY SOILS (LITTLE OR NO FINES) bo c 00000 GP POORLY-GRADED GRAVELS, GRAVEL - SAND MIXTURES, LITTLE ORNOFINES COARSE GRAINED SOILS MORE THAN 5O% OF COARSE FRACTION GRAVELS WITH FINES ° OG D J:ftt:) '' SILTY GRAVELS, GRAVEL - SAND - SILT MIXTURES 6Z"Q5' RETAINED ON NO. 4 SIEVE (APPRECIABLE AMOUNT OF FINES) GC CLAYEY GRAVELS, GRAVEL - SAND - CLAY MIXTURES SAND AND CLEAN SANDS %AI VV WELL-GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES MORE THAN 50% OF MATERIAL IS LARGER THAN SANDY NO. 200 SIEVE SIZE " SOILS (LITTLE OR NO FINES) : :1 :..:.: . :.z . 5 P POORLY-GRADED SANDS, GRAVELLY SAND, LITTLE OR NO FINES SANDS WITH FINES I SM SILTY SANDS SAND SILT MIXTURES MORE THAN 5O% OF COARSE FRACTION PASSING ON NO. 4 SIEVE AMOUNT OF FINES) SC CLAYEY SANDS, SAND - CLAY MIXTURES INORGANIC SILTS AND VERY FINE ML SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS FINE GRAINED SOILS SILTS AND LIQUID LIMIT CLAYS LESS THAN 50 OL ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY MORE THAN 50% OF MATERIAL IS NO. 200 SIEVE SMALLER THAN MH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SAND OR SILTY SOILS SIZE SILTS LIQUID LIMIT CLAYS AND GREATER THAN 50 CH INORGANIC CLAYS OF HIGH PLASTICITY OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS HIGHLY ORGANIC I I d SOILS 11 ,, 11 ,, ,, , PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS SOUTHERN BORING NO. CALIFORNIA B-I CEOTECHNICAL JOB NO.: 07G227 DRILLING DATE: 12/28107 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 13 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RESULTS o a. < a 0 DESCRIPTION SURFACE ELEVATION: 304 feet MSL LABORATORY RESULTS 2 W o 0 p w W U- x I— E W o - W —J < Z o 0 -' oU) - 5 Z >G O o. u s2z 00 o 5 a CL Z1 - a UJU- Z CC 0< ow zx DC!) 10--- 15- - — 74 72/9" 8/11 62 60 H 67 - SANTIAGO FORMATION BEDROCK: White Sandy Siltstone, 77 some Iron oxide staining, friable, very dense-damp 108 111 109 106 107 11 13 17 12 20 14 19 - Light Gray to Light Brown Siltstone, trace fine Sandy Silt layers, some Clay, thinly bedded, some calcareous nodules, very dense-damp to moist - Light Gray to Light Brown Silty Sandstone, some Iron oxide staining, friable, very dense-damp Light Brown Sandy Siltstone, some calcareous veining, friable, very dense-damp to moist Boring Terminated at 191/2 TEST BORING LOG PLATE B-I SOUTHERN BORING NO. CALIFORNIA B-2 GEOTECIINICAL JOB NO.: 07G227 DRILLING DATE: 12/28/07 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 16 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion HELD RESULTS 0 DESCRIPTION LABORATORY RESULTS W Z a. (n LU wu_ co , SURFACE ELEVATION: 306 feet MSL . 8 8 ELi,,L.Light Brown to Brown fine Sand, trace medium Sand, - .•: trace Silt, trace Iron oxide staining, medium dense-moist X 25 12 X 22 16 :T FILL: Orange to Gray Silty fine Sand, trace medium Sand. 45 X dense-moist 14 SANTIAGO FORMATION BEDROCK: Light Gray to Light 40 Brown Silty fine Sandstone, some Iron oxide staining, 16 X dense-moist 10-- . X 26 21 15 Red Brown Siltstone, trace fine Sand, trace calcareous ? veining, dense-moist to very moist - 28 Boring Terminated at 191/2 TEST BORING LOG PLATE B-2 SOUTHERN BORING NO. CALIFORNIA B-3 GEOTECHNICAL JOB NO.: 07G227 DRILLING DATE: 12/28/07 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 16 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RESULTS 0 0 < SURFACE ELEVATION: 307 feet MSL 0 DESCRIPTION _j C LABORATORY RESULTS co I-z 0 o p Lu u_ I W o < i, Z M ou o.b z >-i' o°O o-2 iu ?z o o 5 CO EQ:: zi 10- 15 65 45 46 54 53 5/11' H79 ::: ftJBrown fine Sand, some Silt, some Shell fragments, little Clay, some Iron oxide staining, dense to very dense-damp to moist 107 107 109 107 111 106 107 9 18 13 14 14 16 18 H 7 SANTIAGO FORMATION BEDROCK: Light Gray Silty Sandstone, trace medium Sand, dense-moist - SANTIAGO FORMATION BEDROCK: Gray fine Sandy Siltstone, friable, dense-moist - H Boring Terminated at 191/2 TEST BORING LOG PLATE B-3 SOUTHERN BORING NO. CALIFORNIA B-4 GEOTECHNICAL JOB NO.: 07G227 DRILLING DATE: 12/28/07 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 12 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RESULTS 9 DESCRIPTION LABORATORY RESULTS U) p W W Z E5 Wzu) WLL IL I-i W O (LI (.) I Z Qt. ZE Z I- 0 0 OU a < LL Ln ZO 0< oW o < - (1)co - - o Q. t 0 SURFACE ELEVATION: 304 feet MSL 00. - 00 o O . . U) 0 o - FILL: Brown Clayey fine Sand, trace medium Sand, trace Shell fragments, medium dense-moist 18 19 / 20 17 5— EiLLight Brown Silty fine Sand, trace calcareous veining, 26 trace Iron oxide staining, medium dense-moist 15 SANTIAGO FORMATION BEDROCK: Gray Silty Sandstone, 23 little Clay, thinly bedded, friable, medium dense to 12 dense-damp to moist 10- - 45-—- 32 - 24 BOring Terminated at 15' TEST BORING LOG PLATE B-4 0 I- 0 LU 0 0 0 Un SOUTHERN BORING NO. CALIFORNIA B-5 GEOTECHNICAL JOB NO.: 07G227 DRILLING DATE: 12/28/07 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 15 feet LOCATION: Carlsbad California LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RESULTS SURFACE ELEVATION: 309 feet MSL 0 DESCRIPTION LABORATORY RESULTS 8 u_ - - - - . 8 10- 15 36 31 31 67 75 41 H45 FILL: Brown Clayey fine Sand, some Silt, some Iron oxide staining, moderately cemented, medium dense-damp 109 107 99 101 111 8 8 15 20 15 14 18 EI=54@0t05 - — SANTIAGO FORMATION BEDROCK: Brown Gray Sandstone, friable, some Iron oxide staining, medium dense-damp to moist - - SANTIAGO FORMATION BEDROCK: Gray fine Sandy Siltstone, little Clay, some Iron oxide staining, medium dense-moist H - - SANTIAGO FORMATION BEDROCK: Gray Sandy Siftstone, friable, dense to very dense-moist - SANTIAGO FORMATION BEDROCK: Gray Silty Sandstone. trace Iron oxide staining, friable, dense-moist - Boring Terminated at 191/2' TEST BORING LOG PLATE B-5 SOUTHERN BORING NO. CALIFORNIA B-6 GEOTECHNICAL JOB NO.: 07G227 DRILLING DATE: 12128/07 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 16 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RESULTS S DESCRIPTION W LABORATORY RESULTS co p w 1— 5 ui LL _j LiJ8 j zLu Z Q. OIL >.G TZ 5i a co O° o.b SURFACE ELEVATION: 308 feet MSL X O a a.. 00 O o O. <., O zx c/) o 0 SANTIAGO FORMATION BEDROCK: Gray Silty Sandstone, friable, abundant Iron oxide staining, dense-damp to moist30 X .20 35 11 5 — X 34 19 SANTIAGO FORMATION BEDROCK: Light Brown to Gray x 41 4.5+ Claystone, trace to some fine Sand. some Iron oxide staining, 20 friable, very stiff to hard-moist 10-- .X 61 4.5 18 15 - 42 4.5+ 23 Boring Terminated at 191/2' TEST BORING LOG PLATE B-6 SOUTHERN BORING NO. CALIFORNIA B-7 GEOTECHNICAL JOB NO.: 07G227 DRILLING DATE: 12/28/07 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 15 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RESULTS I < DESCRIPTION SURFACE ELEVATION: 312 feet MSL LABORATORY RESULTS W 0 o p w w LL I.- LU o 0.o w - 0 < U) i- Z 0 -J w a. W o"- QU) Cn >u- c 0 o.2 - Lu Oo o 0 01 ot WZ(/) (b zo:: ow zi u, 10- X 15— 26 46 '5/1I' 7719" 37111' 63 35 SANTIAGO FORMATION BEDROCK: Gray Silty fine grained Sandstone. little Iron oxide staining, dense-moist . 105 103 104 107 109 15 12 11 13 14 18 23 H A A SANTIAGO FORMATION BEDROCK: Gray Silty fine grained Sandstone, some Iron oxide staining, trace medium Sand, very dense-damp to moist H - H - H — Boring Terminated at 191/2 TEST BORING LOG PLATE B-7 SOUTHERN BORING NO. CALIFORNIA B-8 GEOTECHNICAL JOB NO.: 07G227 DRILLING DATE: 12/28107 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 16 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RESULTS DESCRIPTION LABORATORY RESULTS p W W Z 5 w WZ UJLL U- I —J 0 W I z 0 Z —Zc Z Ui - 0 (1 0, Ii - W< —J SURFACE ELEVATION: 314 feet MSL o a.. O 20 0 Zi 75 o zi <N ü-t ZI o, 0 0 SANTIAGO FORMATION BEDROCK: Orange to Gray fine grained Sandstone, some Silt, dense to very dense-moist X 46 14 -x 61 14 5— 46 13 51 17 10- - x 60 21 15 - 68 16 Boring Terminated at 191/2 TEST BORING LOG PLATE B8 1—. Consolidation/Collapse Test Results :EH MZfdat III:H 4 - __ __ . . . ,0•°• • . .. .. .•. o8 . . ---- .. :''-. . . .... ,. s... U, 0 U0 10 ----- ... 12 ---..- -- ---. 14 . 16 0.1 1 10 100 Load (ksf) Classification: FILL: Brown fine Sand, some Silt, some Shell material Boring Number: B-3 Initial Moisture Content (%) 8 Sample Number: --- Final Moisture Content (%) 18 Depth (ft) 1 to 2 Initial Dry Density (pcf) 109.3 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 119.5 Specimen Thickness (in) 1.0 Percent Collapse (%) 2.40 [Bressi PA 3 Lots 10-13 SOUTHERN Carlsbad, California CALIFORNIA Project No. 07G227 "*low GEOTECHNICAL Classification: FILL: Brown fine Sand, some Silt, some Shell material Boring Number: B-3 Initial Moisture Content (%) 18 Sample Number: --- Final Moisture Content (%) 25 Depth (ft) 3 to 4 Initial Dry Density (pcf) 104.9 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 110.6 Specimen Thickness (in) 1.0 Percent Collapse (%) 0.37 Bressi PA 3 Lots 10-13 - SOUTHERN Carlsbad, California .• . CALIFORNIA Project No. 07G227 GEOTECHNICAL PLATE C- 2 - ........ Consolidation/Collapse Test Results ate ed at 1600 psf U0 10-- 14 16 0.1 1 10 100 Load (ksf) Classification: BEDROCK: Light Gray Silty Sandstone Boring Number: B-3 Initial Moisture Content (%) 13 Sample Number: Final Moisture Content (%) 19 Depth (It) 5 to 6 Initial Dry Density (pcI) 108.9 Specimen Diameter (in) 2.4 Final Dry Density (pcI) 116.8 Specimen Thickness (in) 1.0 Percent Collapse (%) 0.45 Bressi PA 3 Lots 10-13 Carlsbad, California Project No. 07G227 PLATE C- 3 SOUTHERN CALIFORNIA I Consolidation/Collapse Test Results 2 water AaOe at 1600 psf 4 ---" C . . ... . C o8 S. ,,5 . S.... S' .5.• C C.) 10 0 . ---- 5----- 12 14- 16 0.1 1 10 100 Load (ksf) Classification: BEDROCK: Light Gray Silty Sandstone Boring Number: B-3 Initial Moisture Content (%) 13 Sample Number: --- Final Moisture Content (%) 19 Depth (ft) 7 to 8 Initial Dry Density (pcf) 108.1 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 117.2 Specimen Thickness (in) 1.0 Percent Collapse (%) 0.62 Bressi PA 3 Lots 10-13 SOUTHERN Carlsbad, California P1OC GEOTECHN1CAL Classification: FILL: Brown fine Sand, some Silt Boring Number: B-5 Initial Moisture Content (%) 9 Sample Number: --- Final Moisture Content (%) 17 Depth (ft) 1 t 2 Initial Dry Density (pcf) 104.2 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 117.3 Specimen Thickness (in) 1.0 Percent Collapse (%) 3.04 Bressi PA 3 Lots 10-13 SOUTHERN Carlsbad, California CALIFORNIA Project No, 07G227 GEOTECHNICAL PLATE E C- 5 Consolidation/Collapse Test Results Added 1 Water 00 10 12 14 16 _______ S - - - - - - - - - - • - - - - 0.1 1 10 100 Load (ksf) Classification: BEDROCK: Brown Gray Sandstone Boring Number: B-5 Initial Moisture Content (%) 8 Sample Number: --- Final Moisture Content (%) 22 Depth (ft) 3 to 4 Initial Dry Density (pcf) 105.3 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 111.1 Specimen Thickness (in) 1.0 Percent Collapse (%) 1.20 Bressi PA 3 Lots 10-13 SOUTHERN Carlsbad, California CALIFORNIA Project No. 07G227 PLATE C- 6 Classification: BEDROCK: Brown Gray Sandstone Boring Number: B-5 Initial Moisture Content (%) 15 Sample Number: --- Final Moisture Content (%) 28 Depth (ft) 5 to 6 Initial Dry Density (pcf) 97.3 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 107.4 Specimen Thickness (in) 1.0 Percent Collapse (%) 1.47 Bressi PA 3 Lots 10-13 SOUTHERN Carlsbad, California -. CALIFORNIA Project No. 07G227 . GEOTECHNICAL PLATE C- 7 Consolidation/Collapse Test Results 0i -TFM 2 Water Add d 1600 psf _IIIIII'at : IIIII 6 C C 08 0 C U0 __ 12 1. _ 10 100 Load (ksf) Classification: BEDROCK: Gray fine Sandy Siltstone Boring Number: B-5 Initial Moisture Content (%) 18 Sample Number: --- Final Moisture Content (%) 21 Depth (ft) 7 to 8 Initial Dry Density (pcf) 102.9 Specimen Diameter (in) 2.4 Final Dry Density (pcf) 108.8 Specimen Thickness (in) 1.0 Percent Collapse (%) 0.14 Bressi PA 3 Lots 10-13 SOUTHERN Carlsbad, California CALIFORNIA Project No. 07G227 GEOTECHNICAL PLATE C- 8 , -oil. qI ....... 64 MOW A TV , - y 16"s I -4 -c- f.r-: - A. A . •. .r.. . . . .. .. * :- •-:-- •;•- , - *.. .. Il ' .f FnA C - .-1 p/ V.'-. ..' - .-. -•.• ..' 'a ,. i'..- F- . . L... .g,.-... 1.. -I , j ,- •', --' *.-.t - -.. tI 4.. -4". •' *4 V *7 4 c 1 $ ,.. .i _) r no OR wh 0, Qw 4 ,\t -$- a"*. 'f/ ---, r loan Tz -,: ':-'c- YOM .1 01 ---': -'-J:-..- Grading Guide Specifications Page 1 GRADING GUIDE SPECIFICATIONS These grading guide specifications are intended to provide typical procedures for grading operations. They are intended to supplement the recommendations contained in the geotechnical investigation report for this project. Should the recommendations in the geotechnical investigation report conflict with the grading guide specifications, the more site specific recommendations in the geotechnical investigation report will govern. General The Earthwork Contractor is responsible for the satisfactory completion of all earthwork in accordance with the plans and geotechnical reports, and in accordance with city, county. and Uniform Building Codes. The Geotechnical Engineer is the representative of the Owner/Builder for the purpose of implementing the report recommendations and guidelines. These duties are not intended to relieve the Earthwork Contractor of any responsibility to perform in a workman-like manner, nor is the Geotechnical Engineer to direct the grading equipment or personnel employed by the Contractor. The Earthwork Contractor is required to notify the Geotechnical Engineer of the anticipated work and schedule so that testing and inspections can be provided. If necessary, work may be stopped and redone if personnel have not been scheduled in advance. The Earthwork Contractor is required to have suitable and sufficient equipment on the job- site to process, moisture condition, mix and compact the amount of fill being placed to the approved compaction. In addition, suitable support equipment should be available to conform with recommendations and guidelines in this report. Canyon cleanouts, overexcavation areas, processed ground to receive fill, key excavations, subdrains and benches should be observed by the Geotechnical Engineer prior to placement of any fill. It is the Earthwork Contractor's responsibility to notify the Geotechnical Engineer of areas that are ready for inspection. Excavation, filling, and subgrade preparation should be performed in a manner and sequence that will provide drainage at all times and proper control of erosion. Precipitation, springs, and seepage water encountered shall be pumped or drained to provide a suitable working surface. The Geotechnical Engineer must be informed of springs or water seepage encountered during grading or foundation construction for possible revision to the recommended construction procedures and/or installation of subdrains. Site Preparation The Earthwork Contractor is responsible for all clearing, grubbing, stripping and site preparation for the project in accordance with the recommendations of the Geotechnical Engineer. If any materials or areas are encountered by the Earthwork Contractor which are suspected of having toxic or environmentally sensitive contamination, the Geotechnical Engineer and Owner/Builder should be notified immediately. Major vegetation should be stripped and disposed of off-site. This includes trees, brush, heavy grasses and any materials considered unsuitable by the Geotechnical Engineer. Grading Guide Specifications Page 2 Underground structures such as basements, cesspools or septic disposal systems, mining shafts, tunnels, wells and pipelines should be removed under the inspection of the Geotechnical Engineer and recommendations provided by the Geotechnical Engineer and/or city, county or state agencies. If such structures are known or found, the Geotechnical Engineer should be notified as soon as possible so that recommendations can be formulated. Any topsoil, slopewash, colluvium, alluvium and rock materials which are considered unsuitable by the Geotechnical Engineer should be removed prior to fill placement. Remaining voids created during site clearing caused by removal of trees, foundations basements, irrigation facilities, etc., should be excavated and filled with compacted fill. Subsequent to clearing and removals, areas to receive fill should be scarified to a depth of 10 to 12 inches, moisture conditioned and compacted The moisture condition of the processed ground should be at or slightly above the optimum moisture content as determined by the Geotechnical Engineer. Depending upon field conditions, this may require air drying or watering together with mixing and/or discing. Compacted Fills Soil materials imported to or excavated on the property may be utilized in the fill, provided each material has been determined to be suitable in the opinion of the Geotechnical Engineer. Unless otherwise approved by the Geotechnical Engineer, all fill materials shall be free of deleterious, organic, or frozen matter, shall contain no chemicals that may result in the material being classified as "contaminated," and shall be very low to non-expansive with a maximum expansion index (El) of 50. The top 12 inches of the compacted fill should have a maximum particle size of 3 inches, and all underlying compacted fill material a maximum 6-inch particle size, except as noted below. All soils should be evaluated and tested by the Geotechnical Engineer. Materials with high expansion potential, low strength, poor gradation or containing organic materials may require removal from the site or selective placement and/or mixing to the satisfaction of the Geotechnical Engineer. Rock fragments or rocks less than 6 inches in their largest dimensions, or as otherwise determined by the Geotechnical Engineer, may be used in compacted fill, provided the distribution and placement is satisfactory in the opinion of the Geotechnical Engineer. Rock fragments or rocks greater than 6 inches should be taken off-site or placed in accordance with recommendations and in areas designated as suitable by the Geotechnical Engineer. Acceptable methods typically include windrows. Oversize materials should not be placed within the range of excavation for foundations, utilities, or pools to facilitate excavations. Rock placement should be kept away from slopes (minimum distance: 15 feet) to facilitate compaction near the slope. Fill materials approved by the Geotechnical Engineer should be placed in areas previously prepared to receive fill and in evenly placed, near horizontal layers at about 6 to 8 inches in loose thickness, or as otherwise determined by the Geotechnical Engineer for the project. Each layer should be moisture conditioned to optimum moisture content, or slightly above, as directed by the Geotechnical Engineer. After proper mixing and/or drying, to evenly distribute the moisture, the layers should be compacted to at least 90 percent of the maximum dry density in compliance with ASTM D-1557-78 unless otherwise indicated. Grading Guide Specifications Page 3 Density and moisture content testing should be performed by the Geotechnical Engineer at random intervals and locations as determined by the Geotechnical Engineer. These tests are intended as an aid to the Earthwork Contractor, so he can evaluate his workmanship, equipment effectiveness and site conditions. The Earthwork Contractor is responsible for compaction as required by the Geotechnical Report(s) and governmental agencies. Fill areas unused for a period of time may require moisture conditioning, processing and recompaction prior to the start of additional filling. The Earthwork Contractor should notify the Geotechnical Engineer of his intent so that an evaluation can be made. Fill placed on ground sloping at a 5-to-1 inclination (horizontal-to-vertical) or steeper should be benched into bedrock or other suitable materials, as directed by the Geotechnical Engineer. Typical details of benching are illustrated on Plates G-2, G-4, and G-5. Cut/fill transition lots should have the cut portion overexcavated to a depth of at least 3 feet and rebuilt with fill (see Plate G-1), as determined by the Geotechnical Engineer. All cut lots should be inspected by the Geotechnical Engineer for fracturing and other bedrock conditions. If necessary, the pads should be overexcavated to a depth of 3 feet and rebuilt with a uniform, more cohesive soil type to impede moisture penetration. Cut portions of pad areas above buttresses or stabilizations should be overexcavated to a depth of 3 feet and rebuilt with uniform, more cohesive compacted fill to impede moisture penetration. Non-structural fill adjacent to structural fill should typically be placed in unison to provide lateral support. Backfill along walls must be placed and compacted with care to ensure that excessive unbalanced lateral pressures do not develop. The type of fill material placed adjacent to below grade walls must be properly tested and approved by the Geotechnical Engineer with consideration of the lateral earth pressure used in the design. Foundations The foundation influence zone is defined as extending one foot horizontally from the outside edge of a footing, and proceeding downward at a % horizontal to 1 vertical (0.5:1) inclination. Where overexcavation beneath a footing subgrade is necessary, it should be conducted so as to encompass the entire foundation influence zone, as described above. - • Compacted fill adjacent to exterior footings should extend at least 12 inches above foundation bearing grade. Compacted fill within the interior of structures should extend to - . the floor subgrade elevation. Fill Slopes The placement and compaction of fill described above applies to all fill slopes. Slope compaction should be accomplished by overfilling the slope, adequately compacting the fill in even layers, including the overfilled zone and cutting the slope back to expose the compacted core Slope compaction may also be achieved by backrolling the slope adequately every 2 to 4 vertical feet during the filling process as well as requiring the earth moving and compaction equipment to work close to the top of the slope. Upon completion of slope construction, the slope face should be compacted with a sheepsfoot connected to a sideboom and then grid rolled. This method of slope compaction should only be used if approved by the Geotechnical Engineer. Grading Guide Specifications Page 4 Sandy soils lacking in adequate cohesion may be unstable for a finished slope condition and therefore should not be placed within 15 horizontal feet of the slope face. All fill slopes should be keyed into bedrock or other suitable material. Fill keys should be at least 15 feet wide and inclined at 2 percent into the slope. For slopes higher than 30 feet, the fill key width should be equal to one-half the height of the slope (see Plate G-5). All fill keys should be cleared of loose slough material prior to geotechnical inspection and should be approved by the Geotechnical Engineer and governmental agencies prior to filling. The cut portion of fill over cut slopes should be made first and inspected by the Geotechnical Engineer for possible stabilization requirements. The fill portion should be adequately keyed through all surficial soils and into bedrock or suitable material. Soils should be removed from the transition zone between the cut and fill portions (see Plate G-2). Cut Slopes All cut slopes should be inspected by the Geotechnical Engineer to determine the need for stabilization. The Earthwork Contractor should notify the Geotechnical Engineer when slope cutting is in progress at intervals of 10 vertical feet. Failure to notify may result in a delay in recommendations. Cut slopes exposing loose, cohesionless sands should be reported to the Geotechnical Engineer for possible stabilization recommendations. All stabilization excavations should be cleared of loose slough material prior to geotechnical inspection. Stakes should be provided by the Civil Engineer to verify the location and dimensions of the key. A typical stabilization fill detail is shown on Plate G-5. Stabilization key excavations should be provided with subdrains. Typical subdrain details are shown on Plates G-6. Subdrains Subdrains may be required in canyons and swales where fill placement is proposed. Typical subdrain details for canyons are shown on Plate G-3. Subdrains should be installed after approval of removals and before filling, as determined by the Soils Engineer. - • Plastic pipe may be used for subdrains provided it is Schedule 40 or SDR 35 or equivalent. Pipe should be protected against breakage, typically by placement in a square-cut (backhoe) trench or as recommended by the manufacturer. - • Filter material for subdrains should conform to CALTRANS Specification 68-1.025 or as approved by the Geotechnical Engineer for the specific site conditions. Clean %-inch crushed rock may be used provided it is wrapped in an acceptable filter cloth and approved - by the Geotechnical Engineer. Pipe diameters should be 6 inches for runs up to 500 feet and 8 inches for the downstream continuations of longer runs. Four-inch diameter pipe may be used in buttress and stabilization fills. 5'MIN. I 3' MIN. OVEREXCAVATE AND 1 RECOMPACT DEEPER OVEREXCAVATION MAY BE RECOMMENDED BY THE SOIL ENGINEER IN STEEP TRANSITIONS CUT LOT GRPIDE I - - - - - - 5MIN COMPACTED FILL. ..... / . ZOVEREXCAVATE AND RECOMPACT COMPETENT MATERIAL, AS APPROVED BY THE GEOTECHNICAL ENGINEER CUT/FILL LOT (TRANSITION) I TRANSITION LOT DETAIL GRADING GUIDE SPECIFICATIONS SOUTHERN NOT TO SCALE DRAWN: JAS CHKD: GNM CALIFORNIA PLATE D-1 SOUTHERN NEW COMPACTED FILL COMPETENT MATERIAL CUT/FILL CONTACT SHOWN CUT/FILL CONTACT TO BE ON GRADING PLAN SHOWN ON "AS-BUILT" NATURAL GRADE CUT SLOPE CUT SLOPE TO BE CONSTRUCTED PRIOR TO PLACEMENT OF FILL 91 M BEDROCK OR APPROVED COMPETENT MATERIAL -,- _- - O ...... . 4'MIN. T. ARIABLE... I MAXIMUM HEIGHT OF BENCHES IS 4 FEET OR AS RECOMMENDED BY THE GEOTECHNICAL ENGINEER -T-MINIMUM 1 TILT BACK OR 2% SLOPE (WHICHEVER IS GREATER) KEYWAY IN COMPETENT MATERIAL MINIMUM WIDTH OF 15 FEET OR AS RECOMMENDED BY THE GEOTECHNICAL ENGINEER. KEYWAY MAY NOT BE REQUIRED IF FILL SLOPE IS LESS THAN 5 FEET IN HEIGHT AS RECOMMENDED BY THE GEOTECHNICAL ENGINEER. \ : IVulIN. 18MIN. ::..'•. •.. •. • MINUS 1" CRUSHED ROCK COMPLETELY .4 4 SURROUNDED BY FILTER FABRIC, OR CLASS II PERMEABLE MATERIAL 18 MIN. L MIN. 6 DIAMETER PERFORATED PIPE - MINIMUM 1% SLOPE PIPE DEPTH OF FILL MATERIAL OVER SUBDRAIN SCHEMATIC ONLY ADS (CORRUGATED POLETHYLENE) 8 NOT TO SCALE TRANSITE UNDERDRAIN 20 PVC OR ABS: SDR35 35 SDR21 100 FINISHED SLOPE FACE NEW COMPACTED FILL OVERFILL REQUIREMENTS PER PLATE NO.4 COMPETENT MATERIAL TOE OF SLOPE SHOWN \ . .TT.•0•• ON GRADING PLAN . •......• ........ PROJECT SLOPE GRADIENT (11 MAX.) . . .... .. . . . ..... .... .: .. ...... PLACE COMPACTED BACKFILL . ...• :. . . .• . . TO ORIGINAL GRADE ... BACKCUT - VARIES -'i > ... . .. _--.•.. . .. . 4' MIN. T c VARIABLE. .... - OVE - MAXIMUM HEIGHT OF BENCHES IS 4 FEET OR AS RECOMMENDED 2' MINIMUM KEY DEPTH KEYWAY IN COMPETENT MATERIAL. MINIMUM WIDTH OF 15 FEET OR AS RECOMMENDED BY THE GEOTECHNIAL ENGINEER. KEYWAY MAY NOT BE REQUIRED IF FILL SLOPE IS LESS THAN 5' IN HEIGHT AS RECOMMENDED BY THE GEOTECHNICAL ENGINEER. NOTE: BENCHING SHALL BE REQUIRED WHEN NATURAL SLOPES ARE EQUAL TO OR STEEPER THAN 5:1 OR WHEN RECOMMENDED BY THE GEOTECHNICAL ENGINEER. BY THE U I tU11NILL ENGINEER MINIMUM 1 TILT BACK OR 2% SLOPE (WHICHEVER IS GREATER) 3' TYPICAL BLANKET FILL IF RECOMMENDED BY THE GEOTECHNICAL ENGINEER TOP WIDTH OF FILL AS SPECIFIED BY THE GEOTECHNICAL ENGINEER COMPETENT MATERIAL ACCEPTABLE TO THE SOIL ENGINEER COMPACTED FILL VARIABLE MINIMUM HEIGHT OF BENCHES IS 4 FEET OR AS RECOMMENDED / BY THE GEOTECHNICAL ENGINEER MINIMUM 1' TILT BACK 2' MINIMUM .-_J _____________________ OR 2% SLOPE KEY DEPTH KEYWAY WIDTH, AS SPECIFIED (WHICHEVER IS GREATER) BY THE GEOTECHNICAL ENGINEER FACE OF FINISHED SLOPE "GRAVEL" TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUIVALENT: MAXIMUM SIEVE SIZE PERCENTAGE PASSING 1 1/2 100 NO.4 50 NO. 200 8 SAND EQUIVALENT = MINIMUM OF 50 OUTLET PIPE TO BE CON- NECTED TO SUBDRAIN PIP' WITH TEE OR ELBOW DESIGN FINISH SLOPE OUTLETS TO BE SPACED AT 100 MAXIMUM INTERVALS. EXTEND 12 INCHES BLANKET FILL IF RECOMMENDED BEYOND FACE OF SLOPE \ BY THE GEOTECHNICAL ENGINEER AT TIME OF ROUGH GRADING CONSTRUCTION. BUTTRESS OR SIDEHILL FILL iô' MI I 25 MAX :..:j DETAIL "A" 4-INCH DIAMETER NON-PERFORATED '- OUTLET PIPE TO BE LOCATED IN FIELD BY THE SOIL ENGINEER. "FILTER MATERIAL" TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUIVALENT: (CONFORMS TO EMA STD. PLAN 323) SIEVE SIZE PERCENTAGE PASSING 1" 100 3/4' 90-100 3/8" 40-100 NO. 4 25-40 NO.8 18-33 NO. 30 5-15 NO. 50 0-7 NO. 200 0-3 FILTER MATERIAL - MINIMUM OF FIVE CUBIC FEET PER FOOT OF PIPE. SEE ABOVE FOR FILTER MATERIAL SPECIFICATION. ALTERNATIVE: IN LIEU OF FILTER MATERIAL FIVE CUBIC FEET OF GRAVEL PER FOOT OF PIPE MAY BE ENCASED IN FILTER FABRIC. SEE ABOVE FOR GRAVEL SPECIFICATION. FILTER FABRIC SHALL BE MIRAFI 140 OR EQUIVALENT. FILTER FABRIC SHALL BE LAPPED A MINIMUM OF 12 INCHES L ON ALL JOINTS. MINIMUM 4-INCH DIAMETER PVC SCH 40 OR ABS CLASS SDR 35 WITH A CRUSHING STRENGTH OF AT LEAST 1,000 POUNDS, WITH A MINIMUM DETAIL 'A OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS ON BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM END OF PIPE. SLOPE AT 2 PERCENT TO OUTLET PIPE. NOTES: 1. TRENCH FOR OUTLET PIPES TO BE BACKFILLED WITH ON-SITE SOIL. "GRAVEL" TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUIVALENT: MAXIMUM SIEVE SIZE PERCENTAGE PASSING 1 1/2" 100 NO.4 50 NO. 200 8 SAND EQUIVALENT = MINIMUM OF 50 MINIMUM ONE FOOT THICK LAYER OF MINIMUM ONE FOOT WIDE LAYER OF LOW PERMEABLILITY SOIL IF NOT FREE DRAINING MATERIAL COVERED WITH AN IMPERMEABLE SURFACE (LESS THAN 5% PASSING THE #200 SIEVE) [FILTER MATERIAL - MINIMUM OF TWO I CUBIC FEET PER FOOT OF PIPE. SEE BELOW FOR FILTER MATERIAL SPECIFICATION. ALTERNATIVE: IN LIEU OF FILTER MATERIAL TWO CUBIC FEET OF GRAVEL PER FOOT OF PIPE MAY BE ENCASED IN FILTER FABRIC. SEE BELOW FOR GRAVEL SPECIFICATION. FILTER FABRIC SHALL BE MIRAFI 140 OR EQUIVALENT. FILTER FABRIC SHALL BE LAPPED A MINIMUM OF 6 INCHES ON ALL JOINTS. MINIMUM 4-INCH DIAMETER PVC SCH 40 OR ABS CLASS SOR 35 WITH A CRUSHING STRENGTH OF AT LEAST 1,000 POUNDS, WITH A MINIMUM OF 8 UNIFORMLY SPACED PERFORATIONS PER FOOT OF PIPE INSTALLED WITH PERFORATIONS ON BOTTOM OF PIPE. PROVIDE CAP AT UPSTREAM END OF PIPE. SLOPE AT 2 PERCENT TO OUTLET PIPE. "FILTER MATERIAL" TO MEET FOLLOWING SPECIFICATION OR APPROVED EQUIVALENT: (CONFORMS TO EMA STD. PLAN 323) SIEVE SIZE PERCENTAGE PASSING 1" 100 3/4 90-100 3/8" 40-100 NO. 4 25-40 NO. 8 18-33 NO, 30 5-15 NO. 50 0-7 NO. 200 0-3 .- ¼ K K K K A 41 -¼' K. .-K K AN K-~ ... ..'-.' . ,1.___,_• K' ''"' : / - Amp i.:'.'.- i': -:.--''- '-.-';. .' - 'tK .K', ., K K , - ______ - I K , ..-. -. . •5f ' ,94' 4 & "4 K V. 4"tr " VIVO OT>g za •--,'5-'-.':F".. OR It xy 34 W, q "'ç -1 K K ""2K. K1 KK jr K - K" - K' ., •'.. K ., " 4. < .--K ''4.•-1''-' K . K. 4 K' K) / •_ • ' KONE- - - ' " C 'K •' K" \ W"s Q4 too flu ,-. 'Y'." :-, .. -.,. -:- 2 •; . ;j-'"K.t;"'. ________....,.. .'..', . -. '.' "..- - ,K4 I' .4.. ' .. ',. - '. , . - ' K -- ' .," ' ''K '-''- 'i' ." "K ,K?K' .'''- - v-'. •- , - .., K' 0 I K 16 NOV 1 nuk"Qm 44 -_,':- . K' K " K K K. K K 0.55 0.50 - 0.45 cu 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 0.80 0.75 0.70i / ::: I' DesignSpecfrum Sa Vs T 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 T (sec) Conterminous 48 States 2006 International Building Code Latitude = 33.12732 Longitude = -117.26537 Spectral Response Accelerations Ss and Si Ss and Si = Mapped Spectral Acceleration Values Site Class B - Fa = 1.0 ,Fv= 1.0 Data are based on a 0.01 deg grid spacing Period Sa (sec) (g) 0.2 1.131 (Ss, Site Class B) 1.0 0.428 (Si, Site Class B) Conterminous 48 States 2006 International Building Code Latitude = 33.12732 Longitude = -117.26537 Spectral Response Accelerations SMs and SM1 SMs = FaSs and SM1 = FvS1 Site Class D - Fa = 1.048 ,Fv = 1.572 Period Sa (sec) (g) 0.2 1.185 (SMs, Site Class D) 1.0 0.673 (SM1, Site Class D) Conterminous 48 States 2006 International Building Code Latitude = 33.12732 Longitude = -117.26537 SDs = 2/3 x SMs and SD1 = 2/3 x SM1 Site Class D - Fa = 1.048 ,Fv = 1.572 Period Sa (sec) (g) 0.2 0.790 (SDs, Site Class D) 1.0 0.449 (SD1, Site Class D) Conterminous 48 States AUG 19 2014 LANu UVLUt-MENT ENGINEERI NG PLAN CHECK NOR,I November 6, 2013 ViaSat, Inc. 6155 El Camino Real Carlsbad, California 92009 Attention: Mr. Bob Rota Vice President, Facilities & Security cvreo3I, SOUTHERN CALIFORNIA 1,r GEOTECHNICAL A C I iiw 1" Ai L I 1 /*.,j; References: 13G176-1 pc••i /FL! -' !. - Plan Review, Update of Geotechnical Report and Additional Subsurface Exploration and Laboratory Testing RECEIVED Proposed Commercial Buildings Bressi Ranch, Planning Area 3, Lots 10-13 JUN 19 2014 NWC Gateway Road and El Camino Road Carlsbad, California LANL) uVELOPMENT ENGINEERING 1) Geotechnical Investigation, Proposed Commercial /Industrial Development, Bressi Ranch Lots 10-13, Planning Area 3, NEC of Gateway Road and El Camino Real, Carlsbad, California, prepared by Southern California Geotechnical, Inc. (SCG), dated January 23, 2008, SCG Project No. 07G227-1. Project No.: Subject: Geotechnical Investigation, Proposed Business Park, Bressi Ranch Lots 10-13, Planninci Area 3, NEC of Gateway Road and El Camino Real, Carlsbad, California, prepared by SCG, dated December 19, 2006, SCG Project No. 06G252-1. Geotechnical Investigation, Proposed Business Park, Bressi Ranch Lots 10-13, Planning Area 3, NEC of Gateway Road and El Camino Real; Carlsbad, California, prepared by SCG, dated November 16, 2005, SCG Project No. 05G273-1. Gentlemen: In accordance with your request, we have prepared this report to update the referenced geotechnical report with respect to site conditions and changes in the building code since the original report was prepared. This report contains updated references to the 2010 California Building Code (CBC), including updated seismic design parameters. In order to prepare this update report, we have reviewed an updated site plan provided to us by Meracon Corporation on September 25, 2013. Current Site Conditions The subject site is located within the recently mass graded Bressi Ranch Industrial Park which is located southeast of the intersection of Palomar Airport Road and El Camino Real in the city of Carlsbad, California. The specific site is a portion of Planning Area 3, Lots 10 through 13, and is located northeast of the intersection of Gateway Road and El Camino Real. The general location of the site is illustrated on the Site Location Map, included as Plate 1 of this letter. 22885 Savi Ranch Parkway Suite E Yorba Linda ' California v' 92887 voice: (714) 685-1115 V fax: (714) 685-1118 V www.socalgeo.com The subject site is an irregularly-shaped parcel, approximately 8± acres in size. Graded slopes ranging in height from 5 to 7± feet border the site to the north and east. Five (5) desilting basins were located throughout the site. The desilting basins were approximately 6 to 8± feet deep. At the time of this subsurface exploration, groundi surface cover consisted of exposed soil with moderate grass and weed growth. Abundant rodent burrows were observed throughout the ground surface. Preliminar topographic information was obtained from a plan prepared by mith Consulting Architects (SCA) for the referenced geotechnical report. The site plan indicates that site grades within Lots 10 through 13 range from elevation 325± feet mean sea level (msl) at the northeastern property corner to an elevation of 295± feet msl at the southwestern property corner. Previous Studies Southern California Geotechnical, Inc., (SCG) previously performed three (3) geotechnical investigation for this site, the results of which were presented in the above referenced geotechnical reports. The reports which are applicable to the subject site are summarized below: Geotechnical Investigation, Proposed Commercial/Industrial Development, Bressi Ranch Lots 10 - 13, Planning Area 3, Carlsbad, California; prepared for Levine Investments by Southern California Geotechnical, Inc., dated January 23, 2008, Project No. 07G227-1. This report presents the results of our previous geotechnical investigation of the subject site. The work documented by this report occurred during the period of December 28, 2007 through January 23, 2008. This report states that eight (8) borings were drilled within the site to depths of 15 to 191/2± feet. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County Department of Environmental Health (DEH). The borings identified engineered fill soils extending to depths of up to 8± feet below existing grade. Below the fill soils and at the ground surface of several borings, Santiago Formation bedrock was observed to the maximum depth explored of 191/2± feet below ground surface. Groundwater was reportedly not encountered during drilling of any of the borings. Corrective grading recommendations were provided in the report. It was recommended that corrective grading removals of shallow bedrock for the two proposed building pad areas. on the order of 3 feet below existing grade and to a depth of 3 feet below proposed pad grade. In addition, the depth of overexcavation was recommended to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations for the proposed buildings. Geotechnical Investigation, Proposed Business Park, Bressi Ranch Lots 10 - 13, Planning Area 3, Carlsbad, California; prepared for Ascent Biltmore, LLC by Southern California Geotechnical, Inc., dated December 19, 2006, Project No. 06G252-1. This report presents the results of our previous geotechnical investigation of the subject site. The work documented by this report occurred during the period of December 1, 2006 through December 19, 2006. This report states that fifteen (15) borings were drilled within the site to a depth of 191/2± feet. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County DEH. The borings identified engineered fill soils extending to depths of 11/2 to 121/2± feet below existing grade. Below the fill soils, Santiago Formation bedrock was observed to the maximum depth explored of 191/2± feet below ground _____ Proposed Commercial Buildings - Carlsbad, CA - Project No 13G176-1 Page 2 surface. Groundwater was reportedly not encountered during drilling of any of the borings. The report identified corrective grading removals of shallow bedrock for the twelve building pad areas on the order of 3 feet below existing grade and to a depth of 3 feet below proposed pad grade. In addition, the depth of overexcavation was recommended to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations for the selected buildings. Geotechnical Investigation, Proposed Business Park, Bressi Ranch Lots 10 - 13, Planning Area 3, Carlsbad, California; prepared for St. Croix Capital by Southern California Geotechnical, Inc., dated November 16, 2005, Project No. 05G273-1. This report presents the results of our previous geotechnical investigation of the subject site. The work documented by this report occurred during the period of October 31, 2005 through November 16, 2005. This report states that eight (8) borings were drilled within the site to depths ranging from 10 to 191/2± feet. The maximum depth of the borings was limited to less than 20 feet due to permit restrictions imposed by the San Diego County DEH. The borings identified engineered fill soils extending to depths of 2 to 21,4± feet below existing grade. Below the fill soils, Santiago Formation bedrock was observed to the maximum depth explored of 191,4± feet below ground surface. Groundwater was reportedly not encountered during drilling of any of the borings. The report identified corrective grading removals of shallow bedrock for the two building pad areas on the order of 3 feet below existing grade and to a depth of 3 feet below proposed pad grade. In addition, the depth of overexcavation was recommended to provide at least 3 feet of new structural fill beneath the bearing grade of all foundations for the selected buildings. Geotechnical Recommendations Concerning 95 Percent Relative Compaction of Fill Deeper than 40 Feet, Bressi Ranch, Carlsbad, California, prepared for Lennar Communities by Leighton and Associates, Inc., dated February 13, 2003, Project No. 971009-007. The three (3) SCG reports listed above all reference this 2003 Leighton report which addresses the settlement potential of deep fill areas and provides recommendations to reduce the time period for the majority of the settlement to occur. In several areas of the overall project, fills up to 40 to 50± feet in thickness were planned to achieve the design grades. Deep fill areas on the subject site are located in the eastern portion of PA-2, and two small areas within PA-3 and PA- 5. The report recommends that all structural fills below a depth of 40 feet from finish grade be compacted to at least 95 percent of the ASTM D-1557 maximum dry density, and estimates that the time period for the majority of the settlement to occur will be reduced from 6 to 12 months to 3 to 8+ months. Near surface settlement monuments were recommended to be installed immediately after rough grading, with survey intervals of once a week for the first month, then twice a month for 3 months, and then monthly to determine completion primary settlement of deep fills. The recommended locations of the near surface settlement monuments are indicated to be contained on an index map within this report, however, the copy provided to us does not contain this plan. Plan Review A detailed grading plan was not available at the time of this report update. However, we were provided with a proposed undated site plan which showed the general location of the two (2) - Proposed Commercial Buildings - Carlsbad, CA CALI0RNIA Project No 13G176-1 'GEOCB1CAL Page 3 proposed buildings. The site plan the proposed development was reviewed with regard to the assumptions, conclusions, and recommendations of the above referenced geotechnical reports. The proposed site plan indicates that two (2) new three-story buildings will be constructed at the subject site. The plan indicates that the western-most building is identified as Building 10 with a total area of 77,400 ft2 and the eastern-most building is identified as Building ii with a total area of 65,700 ft2. It is our assumed that the new buildings buildings will beof concrete tilt-up construction typically supported on conventional shallow foundation systems and concrete slabs on grade with no basement structures. Based on the assumed construction, maximum column and wall loads are expected to be on the order of 60 to 80 kips and 3 to 5 kips per linear foot, respectively. Comments generated during our review of these plans are presented below: Based on information provided to us by the client, Building 10 is located in the same vicinity as Borings B-il and B-13 of SCG report 06G252-1 and Boring B-i of SCG report 07G227-1. Based on information provided to us by the client, Building ii is located in the same vicinity as Borings B-5 and B-10 of SCG report 06G252-1 and Boring B-7 of SCG report 07G227-1. Based on information provided to us by the client and on our previous geotechnical investigations, the western half of proposed Building 10 is presently underlain by fill soils and the eastern half of Building 10 is presently underlain by Santiago Formation bedrock. Based on information provided to us by the client and on our previous geotechnical investigations, proposed Building ii is presently. entirely underlain by Santiago formation bedrock. The site plan indicates that several bioretention systems will be constructed throughout the site. Based on conversations with the project civil engineer, it is our understanding that the biorentention system will be designed such that no water entering the bioretention system will be allowed to infiltrate and/or percolate into the surrounding soils via the properly designed and installed water-proof plastic liners. Once the full set of grading plans has been developed, it is recommended that the geotechnical engineer review these plans for conformance with the geotechnical report. Seismic Design Parameters As of January 1, 2011, the 2010 CBC was adopted by all municipalities within Southern California. The CBC provides procedures for earthquake resistant structural design that include considerations for on-site soil conditions, occupancy, and the configuration of the structure including the structural system and height. The seismic design parameters presented below are based on the soil profile and the proximity of known faults with respect to the subject site. The 2010 CBC Seismic Design Parameters have been generated using Earthquake Ground Motion Parameters, a software application developed by the United States Geological Survey. This software application, available at the USGS web site calculates seismic design parameters in Proposed Commercial Buiichngs — Carisbad,CA Project No. 13G176-1 LIF Page 4 accordance with the 2010 CBC, utilizing a database of deterministic site accelerations at 0.01 degree intervals. The table below is a compilation of the data provided by the USGS application. 2010 CBC SEISMIC DESIGN PARAMETERS Parameter Value Mapped Spectral Acceleration at 0.2 sec Period Ss 1.129 Mapped Spectral Acceleration at 1.0 sec Period S1 0.427 Site Class --- D Short-Period Site Coefficient at 0.2 sec Period Fa 1.048 Long-Period Site Coefficient at 1.0 sec Period Fv 1.573 Site Modified Spectral Acceleration at 0.2 sec Period SMS 1.183 Site Modified Spectral Acceleration at 1.0 sec Period SM1 0.672 Design Spectral Acceleration at 0.2 sec Period Sos 0.789 Design Spectral Acceleration at 1.0 sec Period SD1 0.448 Seismic Lateral Earth Pressures In addition to the lateral earth pressures presented in Section 6.7 of the above referenced report, the 2010 CBC requires that for structures assigned to Seismic Design Categories D through F, retaining walls should be designed for lateral earth pressures due to earthquake motion. The recommended seismic pressure distribution is triangular in shape, with a maximum magnitude of 16H lbs/ft2, where H is the overall height of the wall. The maximum pressure should be assumed to occur at the top of the wall, decreasing to 0 at the base of the wall. The seismic pressure distribution is based on the Mononobe-Okabe equation, utilizing a peak ground acceleration of 0.32g. This peak site acceleration was obtained in accordance with the 2010 CBC, and is equal to SDs/2.5. Limited Exploration/Samplinci Methods We were specifically requested by Smith Consulting Architects, the project architect, to perform laboratory testing for soils in the vicinity of the proposed buildings. Therefore, the subsurface exploration conducted for this phase of the project consisted of two (2) borings advanced to depths of 3 to 31/2± feet below currently existing site grades in order to collect surficial soil samples for laboratory testing. Both of the borings were logged during excavation by a member of our staff. Representative bulk and in-situ soil samples were taken during drilling. Relatively undisturbed in-situ samples were taken with a split barrel "California Sampler" containing a series of one inch long, 2.416± inch diameter brass rings. The bulk samples were collected in plastic bags to retain their original moisture content. The relatively undisturbed ring samples were placed in molded plastic sleeves that were then sealed and transported to our laboratory. The approximate locations of the borings are indicated on the Boring Location Plan, included as Plate 2 of this letter report. The Boring Logs, which illustrate the conditions encountered at the Proposed Commercial Buildings - Carlsbad, CA NW~G[ Project No. 13G176-1 C, OfORNIk Page 5 boring locations, as well as some of the results of the laboratory testing, are included in this report. Geotechnical Conditions Presented below is a generalized summary of the subsurface conditions encountered at the boring locations. More detailed descriptions of the conditions encountered are illustrated on the Boring Logs, included in this report. Artificial Fill Artificial fill soils were encountered at the ground surface at Boring B-i. These fill soils extend to depths of 2± feet below existing grade. As previously discussed, the fill soils within other areas of PA-3 are documented to have maximum depths of 40 to 50± feet. The fill soils encountered in this boring generally consist of dense silty fine sands. The fill soils possess moderately high strengths, moisture contents near or above optimum and based on their color mottling and composition, appeared to be well mixed. Bedrock Bedrock was encountered at the ground surface or beneath the fill soils at both of the boring locations. The bedrock encountered at this site consists of Tertiary age Santiago Formation, which is comprised of dense to very dense sandstone. Bedding within the Santiago Formation on site is generally massive with no significant planes of weakness or discontinuities. The sandstone unit is typically light gray in color, contains moderate iron oxide staining, and is comprised of weakly cemented silty fine sands. Groundwater Based on the water level measurements, and the moisture contents of the recovered soil samples, the static groundwater table is considered to have existed at a depth in excess of 31/2± feet at the time of the subsurface exploration. Further, based on the conditions documented in the mass grading report by Leighton, no groundwater was encountered during grading. Therefore, groundwater is expected to be at depths greater than the extent of the fill soils, which are 40 to 50± feet thick within PA-3. Geologic Conditions Geologic research indicates that the site is underlain by sandstone mapped as the Santiago Formation (Map Symbol Tsa) with nearly horizontal bedding attitudes. The primary available reference applicable to the subject site is DMG Open-File Report 96-02, Geologic Map of the Northwestern Part of San Diego County, California, by California Division of Mines and Geology, 1996. Based on the materials encountered in the exploratory borings, it is our opinion the site is underlain by sandstone bedrock consisting of the Santiago Formation (Map Symbol Tsa). The bedrock encountered in the exploratory borings and observed at the ground surface is generally massively bedded with some moderately developed joints in the upper, less weathered portions of the bedrock. Proposed Commercial Buildings - Carlsbad, CA . '11W 17: CALIFOI4IA Project No 13G176-1 Page 6 Undated Laboratory Testing The soil samples recovered from the subsurface exploration were returned to our laboratory for further testing to determine selected physical and engineering properties of the soils. The tests are briefly discussed below. It should be noted that the test results are specific to the actual samples tested, and variations could be expected at other locations and depths. Classification All recovered soil samples were classified using the Unified Soil Classification System (USCS), in accordance with ASTM D-2488. Field identifications were then supplemented with additional visual classifications and/or by laboratory testing. The USCS classifications are shown on the Boring Logs and are periodically referenced throughout this report. In-situ Density and Moisture Content The density has been determined for selected relatively undisturbed ring samples. These densities were determined in general accordance with the method presented in ASTM D-2937. The results are recorded as dry unit weight in pounds per cubic foot. The moisture contents are determined in accordance with ASTM D-2216, and are expressed as a percentage of the dry weight. These test results are presented on the Boring Logs. Resistivity and DH Testing The resistivity of the soils is a measure of their potential to attack buried metal improvements such as utility lines. The results of the resistivity and pH testing are presented below. These test results are as follows: Sample Identification Resistivity (ohm-cm) pH B-i © 0 to 31/2 feet 1,400 8.0 B-2 © 0 to 3 feet 9,700 8.1 Soluble Sulfates A representative sample of the near-surface soils was submitted to a subcontracted analytical laboratory for determination of soluble sulfate content. Soluble sulfates are naturally present in soils, and if the concentration is high enough, can result in degradation of concrete which comes into contact with these soils. The results of the soluble sulfate testing are presented below, and are discussed further in a subsequent section of this report. Sample Identification Soluble Sulfates (%) CBC Classification B-i © 0 to 31/2 feet 0.141 Moderate B-2 © 0 to 3 feet 0.003 Negligible Proposed Commercial Buildings - Carlsbad, CA Project No. 13G176-1 Page 7 Undated Soluble Sulfate-related Recommendations The results of the soluble sulfate testing indicate that the selected sample of the on-site soils contains a level of soluble sulfates that is classified as having a moderate potential to attack concrete, in accordance with the American Concrete Institute (ACI) Publication 318-05 Building Code Requirements for Structural Concrete and Commentary. Section 4.3. Therefore, it is recommended that a sulfate-resistant concrete mix design be utilized for the foundations and floor slabs at this site. In accordance with the ACI requirements, it is recommended that this concrete incorporate the following characteristics: Cement Type: II (Five) Minimum Compressive Strength (f') = 4,000 lbs/in2 Maximum Water/Cement Ratio: 0.50 It is recommended that additional sulfate testing be performed at the completion of rough grading to verify the concentrations which are present in the actual building pad subgrade soils. Corrosion Potential The results of the electrical resistivity and pH testing indicate that samples of the on-site soils have resistivities of 1400 to 9700 ohm-cm, and pH values of 8.0 and 8.1. These test results have been evaluated in accordance with guidelines published by the Ductile Iron Pipe Research Association (DIPRA). The DIPRA guidelines consist of a point system by which characteristics of the soils are used to quantify the corrosivity characteristics of the site. Resistivity and pH are two of the five factors that enter into the evaluation procedure. Relative soil moisture content as well as redox potential and sulfides are also included. Although redox potential and sulfide testing were not part of the scope of services for this project, we have evaluated the corrosivity characteristics of the on-site soils using resistivity, pH and moisture content. Based on these frpj' factors, and utilizing the DIPRA procedure, some of the on-site soils are considered to be severely corrosive to ductile iron pipe. Therefore, it is expected that polyethylene encasement will be required for ductile iron pipe. The client may also wish to contact a corrosion engineer to provide a more thorough evaluation. Further Plan Reviews S It is recommended that copies of the final grading plans, when they become available, also be provided to our office for review. We also recommend that our office review the foundations plans for the proposed development, as they become available. Geotechnical Report Undate This letter may serve as an update to the original geotechnical report. Provided that the update recommendations contained within this letter are implemented, the original 07G227-1 geotechnical report dated January 23, 2008 is considered valid for the currently proposed development. Proposed Commercial Buildings - Carlsbad, CA Project No. 13G176-1 Page 8 Closure We sincerely appreciate the opportunity to be of continued service on this project. We look forward to providing additional consulting services during the course of the project. If we may be of further assistance in any manner, please contact our office. Respectfully Submitted, SOUTHERN CALIFORNIA GEOTECHNICAL, INC. 1 Robert G. Trazo, M.Sc., GE 2655 No. 2655 JJ) Principal Engineer Distribution: (4) Addressee cfr Enclosures: Plate 1 - Site Location Map Plate 2 - Boring Location Plan Boring Logs B-i and B-2 from current investigation Boring Logs B-i and B-5 from SCG report 07G227-1 Boring Logs B-5, B-iO, B-13, and B-15 from SCG report 06G252-1 Seismic Design Parameters (2 Pages) Proposed Commercial Buildings - Carlsbad, CA CLIFORIA Project No 13G176-1 ,çwrcINiCAL Page 9 - pM; " ,j' MftIA AS 9. 45 A = A A' M1Th4/K - k.,:•= :.., '") .., " r - '(So tRFOPS P LO R J1 - ' 1 • -.--- -ti - : ; A s'J 4, 5''. id, CT p ET 4juE OR :- 5 " A SEE A7 ST t 3 CREST - - ' ,'-...... .4 A', - •- . . . ,,::. . 'A a ALGA ., y oxatmw . . . .* lT' a BERERIA RD tW 1410 Fo cr 11-PIP 110 CRTW 51, Q Mai ml LF RD th IND SITE LOCATION MAP I PROPOSED COMMERCIAL BUILDINGS 01") CARLSBAD, CALIFORNIA SOURCE: ORANGE COUNTY SCALE: V = 2400' THOMAS GUIDE 2008 DRAWN BI SCG PROJECT ' GEOTECHNIAL PLATE - j_ loom . MAIN !1.II!T / CENTRAL PLAZA K -- \\\• \'\ \ -'-- tiuti!i1% - B-7 ' ' Bid a. PHAS'2 65,700 S.F. 45 TALL 3 STORY OFFICE BUILDING FIRE SPRINKLED 1B-1 ' ' \ GEOTECHNICAL LEGEND APPROXIMATE BORING LOCATION PREVIOUS BORING LOCATION ' (SCG PROJECT NO. 07G277-1) + PREVIOUS BORING LOCATION (SCG PROJECT NO. 06G252-1) + PREVIOUS BORING LOCATION (SCG PROJECT NO. 05G273-1) If OFFICE BUILDING PLAZA / 1 45' TALL 3 STO ENTRY / WFIRE SPRINKLED PHASE 1 PHASE 2 \ , fe 7\--'Standard 272 127 Compact 28 109 H. C. 6 6 'Tr%tI 306 OA.- ...... / / I 1/ — / ° / (7 - < t \\(Dellvery truck prkIng pmVided for each'uII1 I / •. i I / -13 - :L- Afe - ENGINEERED FILL isa - SANTIAGO FORMATION - - - GEOLOGIC CONTACT NOTE: BASE MAP PROVIDED BY SMITH CONSULTING ARCHITECTS @ W-F CALIFORNIA , GEOTECHNICAL A CafifmdaQrmffi,n BORING NO. B-I JOB NO.: 13G176 DRILLING DATE: 10/23/13 WATER DEPTH: Dry PROJECT: Commercial Buildings DRILLING METHOD: Hand Auger CAVE DEPTH: 3 feet LOCATION: Carlsbad, California LOGGED BY: Brett Isen READINGTAKEN:At Completion FIELD RESULTS DESCRIPTION LABORATORY RESULTS U) P W o 5 W 2: U) U- - -J 0 w o I z uJ p Z— Zci z 0 -. ()U < . >u. 51— — (1)1 CD 5 cn O< w o < U) -J U) 0 SURFACEELEVATION: --- MSL o o o 0 o < nt z 0 0 —IL—L.Orange Brown Silty fine Sand, little Silt, trace medium Sand, trace Shell fragments, dense-damp 10 10 SANTIAGOFORMATION:Light Gray Silty fine grained Sandstone, very dense-damp Boring Terminated at 3' TEST BORING LOG PLATE B-I W SOUTHERN * CALIFORNIA , GEOTECHNICAL BORING NO. B-2 JOB NO.: 13G176 DRILLING DATE: 10/23/13 WATER DEPTH: Dry PROJECT: Commercial Buildings DRILLING METHOD: Hand Auger CAVE DEPTH: 3.5 feet LOCATION: Carlsbad, California LOGGEDBY:BrettIsen READING TAKEN: At Completion FIELD RESULTS DESCRIPTION LABORATORY RESULTS (I) P W I- D w zu U- I—i 0 W 0 z z uJ I- O o OU- 0 < Co z J - 0< ow W a - < co - -J m - b o SURFACE ELEVATION: ___MSL O a öo o 0 ot zi c/) o o - SANTIAGOFORMATION:Light Gray Brown to Light Gray Silty fine grained Sandstone, trace Iron oxide staining, dense to very dense-damp - 10 Boring Terminated at 31,4 TEST BORING LOG PLATE B-2 W SOUTHERN CALIFORNIA CEOTECHNICAL A 004a CraH,n BORING NO. B-I JOB NO.: 07G227 DRILLING DATE: 12/28/07 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 13 feet LOCATION: Carlsbad, California LOGGED BY: Tim Smith READING TAKEN: At Completion FIELD RESULTS 8 0 a. < DESCRIPTION SURFACE ELEVATION: 304 feet MSL ow W LABORATORY RESULTS U) z LIJ o 0 p W I- W o - uj O < ca — I- O O —J ED — -. Ok'- U) a. b U) z >- ° 00- . 0Z öo o 0 F•• G i n o j (I a. n W o FL Z-Q E5O< ca° < a. it wu_ z(/) b Z ow z (n , 10__ 15 77 67 74 72/9" 8/11' 62 60 — SANTIAGO FORMATION BEDROCK: White Sandy Siltstone, some Iron oxide staining, friable, very dense-damp 108 111 109 106 107 11 13 17 12 20 14 19 Light Gray to Light Brown Siltstone, trace fine Sandy Silt layers, some Clay, thinly bedded, some calcareous nodules, very dense-damp to moist Light Gray to Light Brown Silty Sandstone, some Iron oxide staining, friable, very dense-damp — Light Brown Sandy Siltstone, some calcareous veining, friable, very dense-damp to moist Boring Terminated at 19h/2 TEST BORING LOG PLATE B-I W SOUTHERN CALIFORNIA 1 GEOTECHNICAL A Califon. 4a Cqpomffon BORING NO. B-7 JOB NO.: 07G227 DRILLING DATE: 12/28/07 WATER DEPTH: Dry PROJECT: Bressi PA 3 Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 15 feet LOCATION: Carlsbad, California LOGGEDBY:TimSmith READINGTAKEN:At Completion FIELD RESULTS 0 o_ o < DESCRIPTION SURFACE ELEVATION:312 feetMSL I - LABORATORY RESULTS z Lu 0 P W U- - I- a. Lu - a- < 0 - 0 o m - W - 0"- 0° a-b 5 z 0 . w LIJ0 o o o a- a-04 t wu_ ZC/) 0 < 10- 15 26 46 5/11 7/11 63 35 - SANTIAGOFORMATIONBEDROCK:Gray Silty fine grained Sandstone, little Iron oxide staining, dense-moist 105 103 104 107 109 15 12 11 13 14 18 23 N - SANTIAGOFORMATIONBEDROCK:Gray Silty fine grained Sandstone, some Iron oxide staining, trace medium Sand, very dense-damp to moist N - N N - x - X Boring Terminated at 191/2' TEST BORING LOG PLATE B-7 W UTHERN , CALIFORNIA GEOTECHNICAL A CntiCt'tpratian BORING NO. B-5 JOB NO.: 06G252 DRILLING DATE: 12/1/06 WATER DEPTH: Dry PROJECT: Bressi Ranch, Lots 10- 13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 12 feet LOCATION: Carlsbad, California LOGGEDBY:DarylKas READINGTAKEN:At Completion FIELD RESULTS Q_ < o DESCRIPTION SURFACE ELEVATION: 311±ft MSL LABORATORY RESULTS Cl) z o o P w W U- I- W o - W -J Q < U) - I- 0 -i - I- W - O ab z >-El o Q°OOO . 2z o a 5 D:i - a 04 . it WZ(l) WU- 0< z DC,) 10-- 15 35 52 60 49 50/2" 41 - _i!i'_ SANTIAGOFORMATIONBEDROCK:Light Gray Silty fine grained Sandstone, trace Iron oxide staining, dense to very dense-damp to moist 103 107 110 107 88 13 14 13 14 18 15 23 X Boring Terminated at 19% TEST BORING LOG PLATE B-5 W SOUTHERN * CALIFORNIA , GEOTECHNICAL A Oitbnin Cw*utiou BORING NO. B-10 JOB NO.: 06G252 DRILLING DATE: 12/1/06 WATER DEPTH: Dry PROJECT: Bressi Ranch, Lots 10- 13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: - LOCATION: Carlsbad, California LOGGEDBY:DarylKas READINGTAKEN:At Completion FIELD RESULTS U I Q.. < o DESCRIPTION SURFACE ELEVATION: 311 ftMSL LABORATORY RESULTS C/) W 0 P w w U- — a. w o — Q- < co — 2 o 0 -J m '.. w -.. oU- o° nb (5 z 0 o . W ° O o 0 - I- ° o W o Z -Z c,) <., o 50o< W LL 2: U) b Ow zz 5- 10- . 15 —--- 44 38 34 42 37 29 - SANTIAGOFORMATIONBEDROCK:Light Gray Silty fine grained Sandstone, trace Iron oxide staining, moderately cemented, dense-damp to moist 11 11 16 15 16 19 - X — X Boring Terminated at 191/2 TEST BORING LOG PLATE B-b W SOUTHERN CALIFORNIA , CEOTECHNICAL A C*h7ir*ia C*'ponttian BORING NO. B-13 JOB NO.: 06G252 DRILLING DATE: 12/1/06 WATER DEPTH: Dry PROJECT: Bressi Ranch, Lots 10- 13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 12 feet LOCATION: Carlsbad, California LOGGEDBY:DarylKas READINGTAKEN:At Completion FIELD RESULTS Q_ < DESCRIPTION SURFACE ELEVATION:301± ftMSL LABORATORY RESULTS U) z W o 0 p W W U- — I—i I— W - Q < U) — 0 0 -J a — W OU- o ;5 z >-- O . . '' 2Z 00 o 5 O - :3 oj ZZ0 ca" ot WU 0< U Do 10- 15 ---- 17 11 29 63 44 39 40 — 4.5+:::. 4.0 4.5+ ELLi: Gray Brown fine Sandy Clay, trace Silt, mottled, medium stiff-moist 101 95 106 101 100 18 19 18 24 24 18 19. El=84@0t05' SANTIAGOFORMATIONBEDROCK:Light Gray Silty fine Sandy Siltstone, Iron oxide staining, dense-damp SANTIAGOFORMATIONBEDROCK:Green Gray Clayey Siltstone, Iron oxide staining, hard-damp SANTIAGOFORMATIONBEDROCK:Green Gray Silty Claystone, iron oxide staining, hard-damp SANTIAGO FORMATION BEDROCK: Light Gray Silty fine grained Sandstone, iron oxide staining, dense-damp ,X — Boring Terminated at 191/2' TEST BORING LOG PLATE B-13 SOUTHERN CALIFORNIA : , CEOTECHNICAL A catrth7 Coqvradmi BORING NO. B-15 JOB NO.: 06G252 DRILLING DATE: 12/1/06 WATER DEPTH: Dry PROJECT: Bressi Ranch, Lots 10-13 DRILLING METHOD: Hollow Stem Auger CAVE DEPTH: 15 feet LOCATION: Carlsbad, California LOGGEDBY:DarylKas READINGTAKEN:At Completion FIELD RESULTS 0 I 0 < DESCRIPTION SURFACE ELEVATION: 301± ft MSL LABORATORY RESULTS z W 0 o p w w U- I-i I- a- w 0 — w O < Cl) — 0 —J m — I- W -.. oU a-b >- 0 a. , S?z 00 o a 5 O i- a. :3 CO o WZ(I) WLL z 0< o zi ju 10__ 15_'X 26 28 40 52 35 28 29 — :.: 1. FILL: Mottled Black, Orange and Gray Silty fine Sand, some Clay, medium dense-moist 99 105 109 111 105 19 19 16 13 21 17 SANTIAGOFORMATIONBEDROCK:Light Gray Silty fine grained Sandstone, trace Iron oxide staining, dense-dry to damp SANTIAGOFORMATIONBEDROCK:Light Gray fine Sandy Siltstone, some Iron oxide staining, medium dense-moist 19 SANTIAGOFORMATIONBEDROCK:Light Gray Silty fine grained Sandstone, trace Iron oxide staining, medium dense-moist Boring Terminated at 191/2' TEST BORING LOG PLATE B-15 Conterminous 48 States 2009 International Building Code Latitude = 33.127827 Longitude = -117.26458999999998 Spectral Response Accelerations Ss and Si Ss and Si = Mapped Spectral Acceleration Values Site Class B - Fa = 1.0 ,Fv = 1.0 Data are based on a 0.01 deg grid spacing Period Sa (sec) (g) 0.2 1.129 (Ss, Site Class B) 1.0 0.427 (Si, Site Class B) Conterminous 48 States 2009 International Building Code Latitude = 33.127827 Longitude = -117.26458999999998 Spectral Response Accelerations SMs and SM1 SMs = Fax Ss and SM1 = Fvx Si Site Class D - Fa = 1.048 ,Fv = 1.573 Period Sa (sec) (g) 0.2 1.183 (SMs, Site Class D) 1.0 0.672 (SM1, Site Class D) Conterminous 48 States 2009 International Building Code Latitude = 33.127827 Longitude = -117.26458999999998 Design Spectral Response Accelerations SDs and SD1 SDs = 2/3 x SMs and SD1 = 2/3 x SM1 Site Class D - Fa = 1.048 ,Fv = 1.573 Period Sa (sec) (g) 0.2 0.789 (SDs, Site Class D) 1.0 0.448 (SD1, Site Class D)